ii

Handbook of Forensic Services

(revised 2007)

Editor

Kim Waggoner

Editorial Assistant

Kathryn H. Suchma

Graphic Design

Sandra D. Holliday

An FBI Laboratory Publication

Federal Bureau of Investigation

Quantico, Virginia

ISBN 978-0-16-079376-9
iii

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . 1

Submitting Evidence . . . . . . . . . . . . . 7

Evidence Examinations . . . . . . . . . . 13

Crime Scene Safety . . . . . . . . . . . . 147

Crime Scene Search . . . . . . . . . . . 171

Index . . . . . . . . . . . . . . . . . . . . . . . 185
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Handbook of Forensic Services 2007

Introduction

The Handbook of Forensic Services provides 

guidance and procedures for safe and efficient 

methods of collecting, preserving, packaging, and 

shipping evidence and describes the forensic 

examinations performed by the FBI’s Laboratory 

Division and Operational Technology Division.

FBI Forensic Services

The successful investigation and prosecution of 

crimes require, in most cases, the collection, 

preservation, and forensic analysis of evidence. 

Forensic analysis of evidence is often crucial to 

determinations of guilt or innocence.

The FBI has one of the largest and most 

comprehensive forensic laboratories in the world, 

and the FBI Laboratory is accredited by the 

American Society of Crime Laboratory Directors/

Laboratory Accreditation Board. The forensic 

services of the FBI Laboratory Division and the 

Operational Technology Division are available to 

the following:

ß FBI field offices and legal attachés.

INTRODUCTION
Handbook of Forensic Services 2007

U.S. attorneys, military tribunals, and other 

federal agencies for civil and criminal matters.

State, county, and municipal law 

enforcement agencies in the United States 

and territorial possessions for criminal 

matters.

All forensic services, including expert witness 

testimonies, are rendered free of cost; however, 

the following limitations apply:

No examination will be conducted on 

evidence that has been previously subjected 

to the same type of examination. Exceptions 

may be granted when there are reasons for a 

reexamination. These reasons should be 

explained in separate letters from the director 

of the laboratory that conducted the original 

examination, the prosecuting attorney, and the 

investigating agency.

No request for an examination will be 

accepted from laboratories having the 

capability of conducting the examination. 

Exceptions may be granted upon approval of 

the FBI Laboratory Director or a designee.

No testimony will be furnished if testimony on 

the same subject and in the same case is 

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provided for the prosecution by another 

expert.

No request for an examination will be 

accepted from a nonfederal law 

enforcement agency in civil matters.

In addition, when submitting evidence to the FBI 

Laboratory, contributors acknowledge the 

following:

FBI examiners will choose appropriate 

technical processes to address the 

contributor’s request for examination. 

Depending on the caseload of the Laboratory 

and the needs of the contributor, evidence 

examinations may be subcontracted.

An FBI Laboratory Report of Examination may 

contain the opinions and/or interpretations of 

the examiner(s) who issued the report. 

Violent Crime Versus Property Crime

The FBI accepts evidence related to all crimes 

under investigation by FBI field offices; however, it 

accepts from state and local law enforcement 

agencies only evidence related to violent crime 

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investigations. The FBI does not routinely accept 

evidence from state and local law enforcement 

agencies in cases involving property crimes 

unless there was personal injury or intent to cause 

personal injury. These guidelines help to ensure 

that the FBI continues to provide timely forensic 

assistance to law enforcement agencies 

investigating crimes of violence or threatened 

violence. Additional restrictions may be imposed 

on case acceptance to achieve this goal.

At the discretion of the FBI Laboratory Director or 

a designee, the FBI may accept evidence from 

property crime cases. Such exceptions will be 

considered on a case-by-case basis and should 

not be regarded as setting a precedent for future 

case acceptance. All accepted cases will be 

afforded the full range of forensic services 

provided by the FBI. 

The following are examples of property crimes 

that are not routinely accepted for examinations:

Arson of unoccupied residential and 

commercial buildings and property.

Explosive incidents and hoaxes targeting 

unoccupied residential and commercial 

buildings and property.

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Vandalism and malicious mischief directed 

toward residential or commercial buildings 

and property.

Nonfatal traffic accidents involving 

speedometer and headlight examinations 

except in cases involving law enforcement 

and government officials.

Hit-and-run automobile accidents not involving 

personal injury.

Automobile theft, except automobile theft 

rings or carjackings.

Breaking and entering.

Burglary.

Minor theft (under $100,000).

Minor fraud (under $100,000).

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Handbook of Forensic Services 2007

SUBMISSIONS

Submitting Evidence 

Requesting Evidence Examinations

All requests for evidence examinations should be 

in writing, on agency letterhead, and addressed to 

the FBI Laboratory Evidence Control Unit, unless 

otherwise indicated in the Examinations section. 

Do not submit multiple cases under a single 

communication. Each case should be submitted 

with a separate communication and packaged 

separately.

All international law enforcement agency/

police requests should be coordinated 

through the appropriate FBI legal attaché 

(LEGAT). LEGATs should fax the request to the 

Evidence Control Unit, 703-632-8334, prior to 

submitting any evidence to the Laboratory. 

Questions concerning international 

submissions should be directed to 

703-632-8360.

Requests for evidence examinations must contain 

the following information:

The submitting contact person’s name, 

agency, address, and telephone number.

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Previous case-identification numbers, 

evidence submissions, and communications 

relating to the case.

Description of the nature and the basic facts 

of the case as they pertain to evidence 

examinations.

The name(s) of and descriptive data about the 

individual(s) involved (subject, suspect, victim, 

or a combination of those categories) and the 

agency-assigned case-identification number.

The name of the prosecutor assigned, if 

available.

A list of the evidence being submitted 

“herewith” (enclosed) or “under separate 

cover.”

Herewith is limited to small items 

of evidence that are not endangered by 

transmitting in an envelope. Write on the 

envelope before placing evidence inside 

to avoid damaging or altering the 

evidence. The written communication 

should state: “Submitted herewith are 

the following items of evidence.”

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Separate cover is used to ship numerous 

or bulky items of evidence. Include a copy 

of the communication requesting the 

examinations. The written communication 

should state: “Submitted under separate 

cover by [list the method of shipment] 

are the following items of evidence.”

What type(s) of examination(s) is/are 

requested.

Where the evidence should be returned and 

where the Laboratory report should be sent. 

A street address must be included.

A statement if the evidence was previously 

examined, if there is local controversy, or if 

other law enforcement agencies have an 

interest in the case.

Packaging and Shipping Evidence

Prior to packaging and shipping evidence, call 

the pertinent unit for specific instructions.

Take precautions to preserve the evidence.

Wrap and seal each item of evidence 

separately to avoid contamination.

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Handbook of Forensic Services 2007

Place the evidence in a clean, dry, and 

previously unused inner container.

Seal the inner container with tamper-evident 

or filament tape.

Affix EVIDENCE and BIOHAZARD labels, if 

appropriate, on the inner container. If any of 

the evidence needs to be examined for latent 

prints, affix a LATENT label on the inner 

container.

Affix the evidence examination request and all 

case information between the inner and outer 

containers.

Place the sealed inner container in a clean, 

dry, and previously unused outer container 

with clean packing materials. Do not use 

loose Styrofoam.

Completely seal the outer container so that 

tampering with the container would be 

evident.

All shipments of suspected or confirmed 

hazardous materials must comply with U.S. 

Department of Transportation and 

International Air Transport Association 

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Handbook of Forensic Services 2007

regulations. Title 49 of the Code of Federal 

Regulations (CFR) lists specific requirements 

that must be observed when preparing 

hazardous materials for shipment by air, land, 

or sea. In addition, the International Air 

Transport Association annually publishes 

Dangerous Goods Regulations detailing how 

to prepare and package shipments for air 

transportation.

Title 49 CFR 172.101 provides a Hazardous 

Materials Table that identifies items 

considered hazardous for the purpose of 

transportation. Title 49 CFR 172.101 also 

addresses special provisions for certain 

materials, hazardous materials 

communications, emergency response 

information, and training requirements for 

shippers. A trained and qualified evidence 

technician must assist with the typing, 

labeling, packaging, and shipping of all 

hazardous materials.

U.S. Department of Transportation regulations 

and the following guidelines must be followed 

when shipping live ammunition:

Package and ship ammunition separately 

from firearm(s).

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Handbook of Forensic Services 2007

The outside of the container must be 

labeled “ORM-D, CARTRIDGES, SMALL 

ARMS.”

The Declaration of Dangerous Goods 

must include the number of packages 

and the gross weight in grams of the 

completed packages. 

Unless otherwise indicated in the 

Examinations section, address the 

outer container as follows:

EVIDENCE CONTROL UNIT

LABORATORY DIVISION 

FEDERAL BUREAU OF INVESTIGATION

2501 INVESTIGATION PARKWAY

QUANTICO VA 22135

Ship evidence by U.S. Postal Service 

Registered Mail, UPS, or FedEx. Record the 

method of shipment and the tracking 

number(s) on the chain-of-custody form.

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Handbook of Forensic Services 2007

EXAMINATIONS

Evidence Examinations

Abrasives . . . . . . . . . . . . . 14 Ink . . . . . . . . . . . . . . . . . . . . 79 

Adhesives . . . . . . . . . . . . 14 Latent Prints . . . . . . . . . . . . 80

Anthropology . . . . . . . . . . 15 Lubricants . . . . . . . . . . . . . . 89

Arson . . . . . . . . . . . . . . . . 17 Metallurgy . . . . . . . . . . . . . . 90

Audio . . . . . . . . . . . . . . . . 18 Missing Persons . . . . . . . . . 94

Bank Security Dyes . . . . . 21 Paint . . . . . . . . . . . . . . . . . 100

Building Materials . . . . . . 22 Pepper Spray

Bullet Jacket Alloys . . . . . 23 or Foam . . . . . . . . . . . . 103

Caulk . . . . . . . . . . . . . . . . 14 Pharmaceuticals . . . . . . . . 104

Chemical Unknowns . . . . 24 Polymers . . . . . . . . . . . . . . 104

Computers . . . . . . . . . . . . 26 Product Tampering . . . . . . 106

Controlled Substances . . 29 Questioned Documents . . 107

Cordage . . . . . . . . . . . . . . 117 Racketeering Records . . . . 31

Crime Scene Surveys, Rope . . . . . . . . . . . . . . . . . 117

Documentation, and Safe Insulation . . . . . . . . . 118

Reconstruction . . . . . . 31 Sealants . . . . . . . . . . . . . . . 14

Cryptanalysis . . . . . . . . . . 31 Serial Numbers . . . . . . . . . 119

Demonstrative Evidence . 33 Shoe Prints . . . . . . . . . . . . 121

Disaster Squad . . . . . . . . 61 Soil . . . . . . . . . . . . . . . . . . 131

DNA . . . . . . . . . . . . . . . . . 33 Special-Event and

Electronic Devices . . . . . . 56 Situational Awareness

Explosives . . . . . . . . . . . . 58 Support . . . . . . . . . . . . . 133

Explosives Residue . . . . . 60 Tape . . . . . . . . . . . . . . . . . 134

Feathers . . . . . . . . . . . . . 62 Tire Treads . . . . . . . . . . . . 121

Fibers . . . . . . . . . . . . . . . . 71 Toolmarks . . . . . . . . . . . . . 135

Firearms . . . . . . . . . . . . . 63 Toxicology . . . . . . . . . . . . . 138

Forensic Facial Imaging . 68 Video . . . . . . . . . . . . . . . . . 141

Glass . . . . . . . . . . . . . . . . 69 Weapons of Mass

Hair . . . . . . . . . . . . . . . . . 71 Destruction . . . . . . . . . 144

Image Analysis . . . . . . . . 72 Wood . . . . . . . . . . . . . . . . 146
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Handbook of Forensic Services 2007

Abrasives Examinations

Examinations may determine the type of abrasive 

material used to sabotage engines or machinery.

Questions concerning abrasives evidence 

should be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Employ personnel familiar with the operations 

and mechanics of engines and machinery to 

recover abrasives.

Abrasives settle in oil and fuel. Submit the oil 

and fuel from the engine pump and/or filters.

Abrasives embed in bearings and other parts. 

Submit the bearings and other parts.

Submit abrasives in heat-sealed or resealable 

plastic bags or paint cans. Do not use paper 

or glass containers. 

Adhesive, Caulk, and Sealant 

Examinations

Adhesives, caulks, and sealants can be compared 

by color and chemical composition with suspected 

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Handbook of Forensic Services 2007

sources. The source and manufacturer of 

adhesives, caulks, and sealants cannot be 

determined by compositional analysis.

Questions concerning adhesive, caulk, 

and sealant evidence should be directed to 

703-632-8441. Follow the evidence submission 

directions, including Requesting Evidence 

Examinations and Packaging and Shipping 

Evidence.

When possible, submit the item to which the 

adhesive, caulk, or sealant is adhered. If this 

is not possible, remove a sample of the 

material with a clean, sharp instrument and 

transfer it to a resealable plastic bag or 

leakproof container such as a film canister or 

plastic pill bottle.

Submit a suspected source. Package 

separately.

Anthropological Examinations

Anthropological examinations can determine 

whether something is a bone and, if so, whether it 

is human or animal in origin. Race, sex, 

approximate height and stature, and approximate 

age at death often can be determined from human 

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remains. Damage to bone such as cuts, bluntforce trauma, and bullet holes also may be 

examined. Personal identifications can be made 

by comparing X-rays of a known individual with 

skeletal remains.

Anthropological examinations usually are 

conducted on bones sent to the Laboratory for 

DNA analysis or facial reproductions.

Questions concerning anthropological 

evidence should be directed to 703-632-8449. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Clean and air-dry bones, if possible. Pack in 

paper bags and wrap in protective material 

such as Bubble Wrap or paper. If tissue is 

present on the skeletal material, refrigerate 

until mailing, and then ship in a Styrofoam 

cooler.

Collect insect samples found on the remains 

in leakproof containers such as film canisters 

or plastic pill bottles. Call the Laboratory at 

703-632-8449 for additional instructions.

Submit medical records and X-rays, if possible.

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Handbook of Forensic Services 2007

Arson Examinations

Arson examinations can determine the presence 

of ignitable liquids introduced to a fire scene. 

Examinations of debris recovered from scenes 

can identify gasoline, fuel oils, and speciality 

solvents. Examinations generally cannot identify 

specific brands.

Search at questioned arson scenes for the 

following items: candles, cigarettes, matchbooks, 

Molotov cocktails, fused chemical masses, or any 

electronic or mechanical devices an arsonist may 

have used. Also search for burn trails on cloth or 

paper, burn trails on carpeted or hardwood floors, 

and the removal of personal property or 

commercial inventory.

Questions concerning arson evidence should 

be directed to 703-632-7641. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Ignitable liquids are volatile and easily lost through 

evaporation. Preserve evidence in airtight 

containers such as metal cans, glass jars, or heatsealed plastic bags approved for fire debris. Do 

not fill the containers to the top. Pack to prevent 

breakage.
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Handbook of Forensic Services 2007

Audio Examinations

Audio examinations are conducted by the FBI’s 

Operational Technology Division (OTD), Digital 

Evidence Laboratory (DEL), Forensic Audio, 

Video, and Image Analysis Unit (FAVIAU). The 

OTD DEL has different acceptance criteria and a 

different physical address than the FBI Laboratory, 

as described below.

Authenticity

Authenticity examinations are conducted to 

determine whether audio recordings are original, 

continuous, unaltered, and consistent with the 

operation of the recording device used to make 

the recording.

Enhancement

Enhancement examinations are conducted to 

selectively reduce interfering noise on audio 

recordings to improve the intelligibility.

Voice Comparisons

Spectrographic examinations compare an 

unknown recorded voice sample with a known 

verbatim voice exemplar produced on a similar 

transmission-and-recording device such as the 

telephone. Decisions regarding spectrographic 

voice comparisons are not conclusive. The results 
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Handbook of Forensic Services 2007

of voice comparisons are provided for 

investigative guidance only.

Signal Analysis

Signal analysis examinations are conducted to 

identify, compare, and interpret such signals as 

gunshots and telephone touch tones.

Damaged Media 

Audio recordings can be repaired, restored, or 

retrieved for playback and examination, if damage 

is not too extensive.

Questions concerning audio examinations 

should be directed to 703-985-1393. Questions 

concerning audio evidence should be directed 

to 703-985-1388. 

Audio examinations may not be submitted directly 

from entities outside the FBI. State, local, or 

international agency cases must be submitted by 

the FBI field office servicing the area and must 

meet one of the following two criteria: 1) the state, 

local, or international case has a nexus to an 

ongoing FBI investigation or 2) the FBI division 

head deems that the case is of enough regional 

importance to merit the dedication of federal 

resources to the state, local, or international case. 

These criteria shall be met with a written 
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Handbook of Forensic Services 2007

statement from the division head (Special Agent in 

Charge). FBI entities may submit cases directly.

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Write-protect the original recording, which 

may include finalizing CD and DVD media.

Submit original audio recordings. 

Identify known and questioned voice samples.

Label the outer container “FRAGILE, 

SENSITIVE ELECTRONIC EQUIPMENT” or 

“FRAGILE, SENSITIVE AUDIO/VIDEO 

MEDIA” and “KEEP AWAY FROM MAGNETS 

OR MAGNETIC FIELDS.”

Address the outer container as follows: 

FORENSIC PROGRAM

BUILDING 27958A 

ENGINEERING RESEARCH FACILITY

FEDERAL BUREAU OF INVESTIGATION

QUANTICO VA 22135

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Handbook of Forensic Services 2007

Bank Security Dye Examinations

Bank dye packs contain dye to stain money and 

clothing and tear gas to disorient a robber. Items 

such as money and clothing can be analyzed for 

the presence of bank security dye and tear gas.

Questions concerning bank security dye 

evidence should be directed to 703-632-8441.

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Only evidence with visible red or pink stains 

will be examined.

Do not submit large stained evidence (e.g., 

car seats). When possible, cut a small sample 

of the stained area and submit in a heatsealed or resealable plastic bag. Collect an 

unstained control sample, package separately, 

and submit it with the dye-stained evidence. 

When cutting is not possible, transfer 

questioned stains by rubbing with a clean (dry 

or wet with alcohol) cotton swab. Use an 

unstained swab as a control. Air-dry the swab 

and pack in a heat-sealed or resealable 

plastic bag. 

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Handbook of Forensic Services 2007

Building Materials Examinations

Examinations can compare building materials 

such as brick, mortar, plaster, stucco, cement, and 

concrete.

Questions concerning building materials 

evidence should be directed to 703-632-8449. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

When building materials are penetrated or 

damaged, debris can adhere to people, 

clothing, tools, bags, and stolen items and can 

transfer to vehicles. If possible, submit the 

evidence to the Laboratory for examiners to 

remove the debris. Package each item of 

evidence in a separate paper bag. Do not 

process tools for latent prints.

Collect known samples from the penetrated or 

damaged areas.

Ship known and questioned debris separately 

to avoid contamination. Submit known and 

questioned debris in leakproof containers 

such as film canisters or plastic pill bottles. Do 

not use paper or glass containers. Pack to 

keep lumps intact. 

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Handbook of Forensic Services 2007

Bullet Jacket Alloy Examinations

Elemental analysis of bullet jackets can be done 

when a bullet has fragmented so that individual 

pieces cannot be used for comparison with testfired ammunition from a firearm or in the absence 

of a firearm or the lead component of the bullet. 

This analysis may be helpful when there are 

multiple shooters and types of jacketed 

ammunition. Alloy classification can differentiate 

among bullet jacket alloys of different manufacturers or among the bullet jacket alloys in 

manufacturers’ production lines.

Questions concerning bullet jacket alloy 

examinations should be directed to 703-632-

8441. Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Ammunition components such as bullets, 

cartridge cases, and shotshell casings can be 

sent via Registered Mail through the U.S. 

Postal Service. Evidence must be packaged 

separately with the date, time, location, 

collector’s name, case number, and evidence 

number written on the container.

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U.S. Department of Transportation regulations 

and the following guidelines must be followed 

when shipping live ammunition:

Package and ship ammunition separately 

from firearm(s).

The outside of the container must be 

labeled “ORM-D, CARTRIDGES, SMALL 

ARMS.”

The Declaration of Dangerous Goods 

must include the number of package(s) 

and the gross weight in grams of the 

completed package(s).

Do not mark bullets, cartridges, cartridge 

cases, shotshells, or shotshell casings. The 

date, time, location, collector’s name, case 

number, and evidence number must be on the 

container. 

Back to the top

Chemical Examinations of General 

Unknowns

General unknowns include powders, liquids, and 

stains that are of indeterminate origin or cannot be 

readily classified. Full identification of an unknown 

may not always be possible; however, general 

classification of a substance is usually achievable. 

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When comparison samples are available, it may 

be possible to comment regarding the consistency 

of the unknown substance compared with a 

known sample.

Call the Laboratory at 703-632-8441 prior to 

submitting general unknowns to ensure that 

the evidence will be accepted for examination. 

The communication accompanying the evidence 

must reference the telephone conversation 

accepting the evidence. 

Questions concerning examinations of general 

unknowns should be directed to 703-632-8441. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Submit powder and liquid samples in 

leakproof containers.

Do not submit large stained evidence. When 

possible, cut a small sample of the stained area 

and submit in a heat-sealed or resealable plastic 

bag. Collect an unstained control sample, 

package separately, and submit it with the stained 

evidence. When cutting is not possible, transfer 

questioned stains by rubbing with a clean (dry or 

wet with alcohol) cotton swab. Use an unstained 

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swab as a control. Air-dry the swab and pack in a 

heat-sealed or resealable plastic bag. 

Back to the top

Computer Examinations

Content

Examinations can determine what type of data 

files are on a computer.

Comparison

Examinations can compare data files with known 

documents and data files.

Transaction

Examinations can determine the time and 

sequence that data files were created.

Extraction

Data files can be extracted from the computer or 

computer storage media.

Deleted Data Files

Deleted data files can be recovered from the 

computer or computer storage media.

Format Conversion

Data files can be converted from one format to 

another.
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Keyword Searching

Data files can be searched for a word or phrase 

and all occurrences recorded.

Passwords

Passwords can be recovered and used to decrypt 

encoded files.

Limited Source Code

Source code can be analyzed and compared.

Call the Computer Analysis Response Team at 

703-985-1302 to request a search or field 

examination. Submit requests at least one 

week in advance.

Obtain as much of the following information as 

possible prior to submitting a request:

Determine the type(s) of computers and 

operating systems.

If applicable, determine the type of network 

software, the location of the network servers, 

and the number of computers on the network.

Determine whether encryption and/or 

password protection is used.

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Specify whether a seizure of computers and 

media or an on-site examination is required. 

Questions concerning computer evidence 

should be directed to 703-985-1302. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

For most examinations, submit only the 

central processing units and the internal and 

external storage media.

Use a sturdy cardboard container when 

shipping computer components. If possible, 

use the original packing case with the fitted 

padding. Use large plastic Bubble Wrap or 

foam rubber pads as packing. Do not use 

loose Styrofoam because it lodges inside 

computers and components and creates static 

charges that can cause data loss or damage 

to circuit boards. Seal the container with a 

strong packing tape.

Pack and ship central processing units in the 

upright position. Label the outside container 

“THIS END UP.”

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Disks, cartridges, tapes, and hard drives must 

be packed to avoid movement during 

shipping.

Label the outer container “FRAGILE, 

SENSITIVE ELECTRONIC EQUIPMENT” and 

“KEEP AWAY FROM MAGNETS OR 

MAGNETIC FIELDS.” 

Address the outer container as follows: 

FORENSIC PROGRAM

BUILDING 27958A 

ENGINEERING RESEARCH FACILITY

FEDERAL BUREAU OF INVESTIGATION

QUANTICO VA 22135

Back to the top

Controlled Substance Examinations

Controlled substance examinations can establish 

trace-drug presence, identity, and quantity.

Bulk Drugs

The Laboratory limits the quantity of bulk drugs 

that it will analyze. Quantities exceeding 100 

grams of suspected marijuana or 10 grams of all 

other suspected drugs including cocaine, 

methamphetamine, and heroin will be returned 

unanalyzed. The Laboratory usually analyzes only 

drugs seized in federal investigations.

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Drug Residue

Requests for drug residue examinations on 

evidence will be accepted only when the evidence 

is properly packaged to avoid contamination. Drug 

residue examinations of currency are performed 

only on a limited basis.

Call the Laboratory at 703-632-8441 prior to 

submitting drugs or currency to ensure that 

the evidence will be accepted for examination. 

The communication accompanying the evidence 

must reference the telephone conversation 

accepting the evidence.

Questions concerning controlled substance 

evidence should be directed to 703-632-8441. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Submit evidence in separate heat-sealed or 

resealable plastic bags.

Fold clothing to preserve trace evidence.

Do not submit used drug field-test kits with 

evidence. 

Back to the top

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Crime Scene Surveys, Documentation, 

and Reconstruction

Visual information specialists receive data from 

the field or travel to the field to collect it. They then 

use the data to prepare two- and threedimensional digital or physical crime scene 

reconstructions as well as computer animations or 

models that depict bullet trajectory, line-of-sight 

analysis, and vehicular-, human-, or objectmovement analysis.

Questions concerning crime scene surveys, 

documentation, and reconstruction should be 

directed to 703-632-8194.

Cryptanalysis and Racketeering 

Record Examinations

Cryptanalysis

Cryptanalysis examinations involve the analysis of 

encoded and enciphered documents used by 

terrorists, foreign intelligence agents, violent 

criminals, street and prison gangs, and organized 

crime groups. Encrypted documents may be faxed 

or e-mailed for immediate decryption. Call 

703-632-7356 or 703-632-7334 for contact 

information.
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Handbook of Forensic Services 2007

Drug Records

Drug records are examined to determine the 

overall scope of the businesses, including the 

hierarchy, type of drugs distributed, gross sales, 

gross or net weights or quantities, price structures, 

and other pertinent information.

Gambling

Gambling examinations include the interpretation 

of records from sports and horse bookmaking 

businesses, Internet gambling operations, 

numbers or lottery operations, and other gambling 

businesses.

Loan-Sharking

Loan-sharking records are examined to determine 

the amounts of the loans, amounts paid in interest 

and principal, number of loans, and interest rates.

Money Laundering

Money-laundering records are examined to 

determine the scope of the operations, the 

amounts laundered, how the funds were 

laundered, and any other illegal activities.

Prostitution

Prostitution records are examined to determine 

the scope of the businesses, including the number 

of employees and their roles, gross and net 
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Handbook of Forensic Services 2007

revenues, and other financial and organizational 

information.

Questions concerning cryptanalysis and 

racketeering record evidence should be 

directed to 703-632-7356 or 703-632-7334. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Back to the top

Demonstrative Evidence

Visual information specialists prepare a wide array 

of demonstrative evidence for investigative and 

prosecutorial purposes. These items include 

charts, maps, diagrams, illustrations, and 

animated and digitally interactive presentations.

Questions concerning demonstrative evidence 

should be directed to 703-632-8194.

DNA Examinations

Deoxyribonucleic acid (DNA) is analyzed in bodyfluid stains and other biological tissues recovered 

from items of evidence. The results of DNA testing 

on evidence samples are compared with the 

results of DNA analysis of reference samples 

collected from known individuals. Such analyses 
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Handbook of Forensic Services 2007

can associate victims and suspects with each 

other, with evidence items, or with a crime scene. 

There are two types of DNA used in forensic 

analyses. Nuclear DNA (nDNA) is the more 

discriminating of the two types and is typically 

analyzed in evidence containing blood, semen, 

saliva, body tissue, and hairs that have tissue at 

their root ends. The power of nDNA testing done 

by the DNA Analysis Unit I (DNAUI) lies in its 

ability to potentially identify an individual as being 

the source of the DNA obtained from an evidence 

item to a reasonable degree of scientific certainty, 

as well as the definitive power of exclusion. 

Additionally, where appropriate, the DNA-typing 

results from evidence items (including items 

related to missing persons) examined in the 

DNAUI may be uploaded into the Combined DNA 

Index System (CODIS) database.

Mitochondrial DNA (mtDNA) is typically analyzed 

in evidence containing naturally shed hairs, hair 

fragments, bones, and teeth. Typically, these 

items contain low concentrations of degraded 

DNA, making them unsuitable for nDNA 

examinations. The high sensitivity of mtDNA 

analysis allows scientists to obtain information 

from old items of evidence associated with cold 

cases, samples from mass disasters, and small 

pieces of evidence containing little biological 
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Handbook of Forensic Services 2007

material. Additionally, the maternal inheritance of 

mtDNA allows scientists to compare a mtDNA 

profile to reference samples from that person’s 

mother, brother(s), sister(s), or any other 

maternally related individuals. All of these 

individuals have the same mtDNA profiles 

because all maternal relatives inherit their mtDNA 

from their mother. Because multiple individuals 

can have the same mtDNA type, unique identifications are not possible using mtDNA analysis. 

However, mtDNA performed by the DNA Analysis 

Unit II is an excellent technique to use for 

obtaining information when nDNA analysis is not 

feasible. Additionally, the mtDNA-typing results 

related to missing-person cases may be uploaded 

into the CODIS database.

Questions concerning nuclear DNA testing 

should be directed to 703-632-8446. Questions 

concerning mitochondrial DNA testing should 

be directed to 703-632-7572. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and

Packaging and Shipping Evidence.

Case Acceptance Policy of the DNA 

Analysis Unit I

The DNAUI accepts FBI cases for serological 

and nDNA analysis. FBI cases are prioritized 

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Handbook of Forensic Services 2007

according to the FBI’s priorities of counterterrorism; cyber-based/high-technology 

crimes; public corruption; civil rights; 

transnational/national criminal organizations/

enterprises; major white-collar crime; 

significant violent crime; and support of local, 

state, federal, and international agencies. This 

includes examinations that characterize 

biological stains and may identify the source 

of a stain on an evidentiary item.

The DNAUI accepts cases from FBI field 

offices and legal attachés (LEGATs); other 

federal agencies (e.g., Bureau of Indian 

Affairs, DEA); U.S. attorneys’ offices; military 

tribunals; and duly constituted state, county, 

and municipal law enforcement agencies in 

the United States and its territories. The 

DNAUI also accepts cases that are submitted 

to the Laboratory from international law 

enforcement agencies through the FBI 

LEGATs.

Cases are accepted provided that:

The submitting agency is not served by 

another government forensic DNA 

laboratory. 

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Handbook of Forensic Services 2007

The submitted case has not been 

examined previously by another 

laboratory. 

Case Consideration Policy

The DNAUI supports the National Missing 

Person DNA Database (NMPDD) Program. 

Cases must be submitted through an NMPDD 

Program Manager for entry into the Biological 

Relatives of Missing Persons or Unidentified 

Human Remains Indexes. The NMPDD 

provides investigators with an opportunity to 

identify missing and unidentified persons on a 

national level. 

The DNAUI maintains the Federal Convicted 

Offender (FCO) Program, which supports the 

collection and nDNA analysis of samples 

collected from more than 500 sites across the 

United States. 

The DNAUI requires known reference 

sample(s) for comparison with evidence 

materials. DNA profiles located in the National 

DNA Index System (NDIS) Convicted 

Offender database cannot be used as 

references.

2.

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Handbook of Forensic Services 2007

The DNAUI does not conduct low-copynumber (LCN) or “touch DNA” examinations 

(i.e., DNA from fingerprints, pieces of paper, 

handled objects, etc.). Items such as steering 

wheels and firearms may be appropriate for 

analysis.

The DNAUI does not perform kinship analysis. 

Questions concerning kinship, paternity/

maternity comparisons, etc., should be 

directed to the DNAUI at 703-632-8446.

As necessary:

DNAUI cases may be prioritized according to 

scheduled trial dates or other case-specific 

information.

The DNAUI does not examine evidence from 

property crime cases unless violence that 

results in bodily harm is used in the 

commission of the crime.

For cases in which the FBI Laboratory has 

conducted previous DNA or serological 

testing, a review of the case file will be 

conducted to determine if additional 

examinations will be conducted.

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Handbook of Forensic Services 2007

Case Acceptance Policy of the DNA 

Analysis Unit II

All FBI cases that meet the suitability guidelines 

(outlined below) will be considered for mtDNA 

analysis in the DNAUII. Cases involving terrorism 

are given highest priority, followed by 

counterintelligence matters and violent crimes. 

Questions regarding case and evidence suitability 

should be directed to the DNAUII at 

703-632-7572.

State and local law enforcement agencies needing 

mtDNA analysis must contact the DNAUII for more 

information regarding evidence submission. 

Agencies may call 703-632-7572 to discuss the 

needs of the investigation and the evidence, 

following the suitability guidelines outlined below. 

Analysis of the evidence will be performed by one 

of the unit’s regional mtDNA laboratories and is 

cost-free to state and local law enforcement 

agencies in the United States and its territories. 

Travel expenses for examiners testifying in state 

and local cases are also paid by the FBI 

Laboratory. FBI entities may refer to the FBI 

Laboratory/DNAUII web page on the FBI intranet 

for additional information on the regional mtDNA 

laboratories. 
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Handbook of Forensic Services 2007

Missing-person cases involving unidentified 

human remains and relatives of missing persons 

are managed and entered into the NDIS in the 

DNAUII by members of the NMPDD Program. 

Evidence from these investigations also 

undergoes mtDNA analysis in the DNAUII or in 

one of the regional mtDNA laboratories. Contact 

the NMPDD Program Manager at 703-632-7582

for questions regarding missing-person evidence 

submission. FBI entities may refer to the FBI 

Laboratory/DNAUII web page on the FBI intranet 

for additional information on the NMPDD Program.

Suitability of Mitochondrial DNA Analysis

Mitochondrial DNA analysis has been applied 

successfully to evidence from violent crimes, 

typically homicide, sexual assault, and assault. It 

is important to remember, however, that mtDNA 

analysis is appropriate in only a small portion of 

cases where mtDNA evidence is present. 

Experience shows that about 75 percent of cases 

in which mtDNA analysis is actually performed 

involve hair evidence where only the hair shaft is 

present. Most often, mtDNA analysis is justified for 

hair evidence when no tissue is present on the 

hair root. Mitochondrial DNA analysis in missingperson cases is appropriate only when bone or 
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Handbook of Forensic Services 2007

teeth specimens can be verified as of human 

origin. 

To avoid the misapplication of mtDNA analysis 

resources, cases must be reviewed carefully for 

their scenarios, the possibility of other tests on 

available evidence (e.g., nDNA), and the selection 

of specimens having the greatest probative value.

Regardless of the type of biological evidence, 

mtDNA analysis generally will not be performed 

when nDNA results exist on items of similar origin. 

For example, if nDNA results are obtained from 

semen identified on a victim’s vaginal swabs and 

there is no allegation of multiple assailants, 

mtDNA analysis would not be performed on an 

associated pubic hair found in the pubic-hair 

combings of the victim. 

Current forensic mtDNA techniques cannot 

effectively distinguish between sources or relative 

quantities of DNA. Consequently, mtDNA is not 

appropriate for evidence containing possible 

mixed sources of DNA such as semen stains from 

sexual assaults. 

Mitochondrial DNA analysis generally will not be 

performed on bloodstains unless the victim’s 

reference samples are not available or other 
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Handbook of Forensic Services 2007

appropriate reference samples are unavailable for 

nDNA analysis. For example, a kidnapping victim 

is missing, but a bloodstain is found in the 

suspect’s vehicle and only a maternal relative’s 

(e.g., mother, sibling) reference sample is 

available for the victim. In that case, mtDNA 

analysis could be conducted using a portion of the 

vehicle bloodstain, the maternal relative’s 

reference sample, and the suspect’s known 

sample. 

Mitochondrial DNA Analysis of Hair Evidence

Mitochondrial DNA analysis should be performed 

on probative hair samples only if they are deemed 

unsuitable for nDNA analysis. Only those hairs 

having greatest probative value should be 

subjected to mtDNA analysis. If several similar 

probative hair specimens are submitted from one 

source of evidence, mtDNA analysis should be 

performed on only 1–2 hairs. For example, if 10 

hairs collected from a victim’s body are 

microscopically associated with the suspect, no 

more than 2 hairs will be analyzed.

Submission guidelines for mtDNA cases must 

include the following points for hair evidence:
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Handbook of Forensic Services 2007

Known victim hair samples (of all types) must 

be submitted to determine whether evidence 

hairs are similar or dissimilar to the victim’s 

hair.

If evidence includes specimens dissimilar to 

the victim, known suspect hair samples (of all 

types) should be obtained. 

Mitochondrial DNA analysis generally will be 

performed on all probative microscopic hair 

associations. In addition, the following types of 

hairs are considered for mtDNA analysis, if 

probative:

Hairs that exhibit “microscopic similarities and 

slight differences” (e.g., because of prolonged 

time between the crime and collection of 

reference samples, environmental or artificial 

changes to hair, or the suitability of reference 

samples or questioned hair).

Hairs that are not suitable for microscopic 

comparison purposes (e.g., body-area hairs, 

hair fragments, or any other factor that 

eliminates the possibility of performing a 

comparison). In such cases, however, the hair 

must be probative (e.g., apparent foreign hair 

in the pubic-hair combing of the victim). 

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Handbook of Forensic Services 2007

Hairs that are suitable for microscopic 

comparison purposes but, for valid reasons, 

are not suitable to compare with the pertinent 

reference sample (e.g., hair deposited 10 

years prior to the collection of the reference 

hair sample, reference sample is from an 

individual whose hair is artificially treated after 

the crime date). Regardless, the hair must be 

probative. 

Unidentified Human Remains

Prior to mtDNA analysis, bone or teeth specimens 

should be examined by a forensic anthropologist 

or odontologist or a similarly qualified individual. 

Submissions of such items should be 

accompanied by a written report that verifies 

human origin by a qualified expert. 

Documenting, Collecting, Packaging, and 

Preserving DNA Evidence

If DNA evidence is not properly documented, 

collected, packaged, and preserved, it will not 

meet the legal and scientific requirements for 

admissibility in a court of law.

If DNA evidence is not properly documented, 

its origin can be questioned.

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Handbook of Forensic Services 2007

If it is not properly collected, biological activity 

can be lost.

If it is not properly packaged, contamination 

can occur.

If it is not properly preserved, decomposition 

and deterioration can occur.

When DNA evidence is transferred by direct or 

secondary (indirect) means, it remains on 

surfaces by absorption or adherence. In general, 

liquid biological evidence is absorbed into 

surfaces, and solid biological evidence adheres to 

surfaces. Collecting, packaging, and preserving 

DNA evidence depends on the liquid or solid state 

and the condition of the evidence.

The more evidence retains its original integrity 

until it reaches the Laboratory, the greater the 

possibility of conducting useful examinations. It 

may be necessary to use a variety of techniques 

to collect suspected body-fluid evidence.

Collecting Known Samples

Blood

Only qualified medical personnel should 

collect blood samples from a person.

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Handbook of Forensic Services 2007

Collect at least two 5-mL tubes of blood in 

purple-top tubes, which contain EDTA as a 

preservative, for DNA analysis. Collect drug or 

alcohol-testing samples in gray-top tubes, 

which contain NaF (sodium fluoride).

Label each tube with the date, time, person’s 

name, location, collector’s name, case 

number, and evidence number. 

Refrigerate, do not freeze, liquid blood 

samples (tubes may break if frozen). Use cold 

packs, not dry ice, during shipping.

Pack liquid blood tubes individually in 

Styrofoam or cylindrical tubes with absorbent 

material surrounding the tubes. 

Package blood samples from different 

individuals separately. 

Label the outer container “KEEP IN A COOL, 

DRY PLACE,” “REFRIGERATE ON 

ARRIVAL,” and “BIOHAZARD.”

Submit to the Laboratory as soon as possible.

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Handbook of Forensic Services 2007

Buccal (Oral) Swabs 

Use clean cotton swabs to collect buccal 

(oral) samples. Rub the inside surfaces of 

the cheeks thoroughly.

Air-dry the swabs and place in clean paper 

or an envelope with sealed corners. Do not 

use plastic containers.

Identify each sample with the date, time, 

person’s name, location, collector’s name, 

case number, and evidence number.

Package oral samples from different 

individuals separately. 

Buccal samples do not need to be 

refrigerated.

Submit to the Laboratory as soon as possible.

If a reference blood or oral sample cannot be 

obtained, an alternate reference sample may 

be submitted (for nuclear examinations only). 

This may include such items as surgical 

samples, Pap smear slides, pulled teeth, or a 

toothbrush or item of clothing known to be 

used solely by the individual of interest.

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Handbook of Forensic Services 2007

Blood on a Person

Absorb suspected liquid blood onto a clean 

cotton cloth or swab. Air-dry the cloth or swab 

and pack in clean paper or an envelope with 

sealed corners. Do not use plastic containers.

Absorb suspected dried blood onto a clean 

cotton cloth or swab moistened with distilled 

water. Air-dry the cloth or swab and pack in 

clean paper or an envelope with sealed 

corners. Do not use plastic containers.

Blood on Surfaces or in Snow or Water

Absorb suspected liquid blood or blood clots 

onto a clean cotton cloth or swab. Air-dry the 

cloth or swab and pack in clean paper or an 

envelope with sealed corners. Do not use 

plastic containers.

Collect suspected blood in snow or water 

immediately to avoid further dilution. Eliminate 

as much snow as possible. Place in a clean, 

airtight container. Freeze the evidence and 

submit to the Laboratory as soon as possible.

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Handbook of Forensic Services 2007

Bloodstains

Air-dry suspected wet bloodstained garments. 

Wrap dried bloodstained garments in clean 

paper. Do not place wet or dried garments in 

plastic or airtight containers. Place all debris 

or residue from the garments in clean paper 

or an envelope with sealed corners.

Air-dry small suspected wet bloodstained 

objects and submit the objects to the 

Laboratory. Preserve bloodstain patterns. 

Avoid creating additional stain patterns during 

drying and packaging. Pack to prevent stain 

removal by abrasive action during shipping. 

Pack in clean paper. Do not use plastic 

containers.

When possible, cut a large sample of 

suspected bloodstains from immovable 

objects with a clean, sharp instrument. Pack 

to prevent stain removal by abrasive action 

during shipping. Pack in clean paper. Do not 

use plastic containers.

Absorb suspected dried bloodstains on 

immovable objects onto a clean cotton cloth 

or swab moistened with distilled water. Air-dry 

the cloth or swab and pack in clean paper or 

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Handbook of Forensic Services 2007

an envelope with sealed corners. Do not use 

plastic containers.

Blood Examination Request Letter

A blood examination request letter must contain 

the following information:

A brief statement of facts relating to the case.

Claims made by the suspect(s) regarding the 

source of the blood.

Whether animal blood is present.

Whether the stains were laundered or diluted 

with other body fluids.

Information regarding the health of the 

victim(s) and suspect(s), including the 

presence of such infections as AIDS, 

hepatitis, and tuberculosis.

Semen and Semen Stains

Absorb suspected liquid semen onto a clean 

cotton cloth or swab. Air-dry the cloth or swab 

and pack in clean paper or an envelope with 

sealed corners. Do not use plastic containers.

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Handbook of Forensic Services 2007

Submit small suspected dry semen-stained 

objects to the Laboratory. Pack to prevent 

stain removal by abrasive action during 

shipping. Pack in clean paper. Do not use 

plastic containers.

When possible, cut a large sample of 

suspected semen stains from immovable 

objects with a clean, sharp instrument. Pack 

to prevent stain removal by abrasive action 

during shipping. Pack in clean paper. Do not 

use plastic containers.

Absorb suspected dried semen stains on 

immovable objects onto a clean cotton cloth 

or swab moistened with distilled water. Air-dry 

the swab or cloth and place in clean paper or 

an envelope with sealed corners. Do not use 

plastic containers.

Note: It is not necessary to collect reference 

seminal fluid for comparison. Refer to the 

Collecting Known Samples section for more 

information. 

Seminal Evidence from Sexual Assault Victims

Sexual assault victims must be medically 

examined in a hospital or a physician’s office 

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Handbook of Forensic Services 2007

using a standard sexual assault evidence kit 

to collect vaginal, oral, and anal evidence.

Refrigerate and submit the evidence to the 

Laboratory as soon as possible.

Saliva and Urine, Other Sources of 

Body-Fluid Evidence

Absorb suspected liquid saliva or urine onto a 

clean cotton cloth or swab. Air-dry the cloth or 

swab and pack in clean paper or an envelope 

with sealed corners. Do not use plastic 

containers.

Submit small suspected dry saliva- or urinestained objects to the Laboratory. Pack to 

prevent stain removal by abrasive action 

during shipping. Pack in clean paper or an 

envelope with sealed corners. Do not use 

plastic containers.

When possible, cut a large sample of 

suspected saliva or urine stains from 

immovable objects with a clean, sharp 

instrument. Pack to prevent stain removal by 

abrasive action during shipping. Pack in clean 

paper. Do not use plastic containers.

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Handbook of Forensic Services 2007

Pick up cigarette butts with gloved hands or 

clean forceps. Do not submit ashes. Air-dry 

and place the cigarette butts from the same 

location (e.g., ashtray) in clean paper or an 

envelope with sealed corners. Do not submit 

the ashtray unless a latent print examination 

is requested. Package the ashtray separately. 

Do not use plastic containers.

Pick up chewing gum with gloved hands or 

clean forceps. Air-dry and place in clean 

paper or an envelope with sealed corners. Do 

not use plastic containers.

Pick up envelopes and stamps with gloved 

hands or clean forceps and place in a clean 

envelope. Do not use plastic containers.

Hair

Pick up hair carefully with clean forceps to 

prevent damaging the root tissue.

Air-dry hair mixed with suspected body fluids.

Package each group of hair separately in 

clean paper or an envelope with sealed 

corners. Do not use plastic containers.

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Handbook of Forensic Services 2007

Refrigerate and submit to the Laboratory as 

soon as possible.

Tissue, Bones, and Teeth

Call the Laboratory at 703-632-7572 prior to 

submitting suspected tissue, bones, or teeth to 

ensure that the evidence will be accepted for 

examination. The communication accompanying 

the evidence must reference the telephone 

conversation accepting the evidence. 

Pick up suspected tissue, bones, and teeth 

with gloved hands or clean forceps.

Collect 1–2 cubic inches of red skeletal 

muscle.

Submit whole bones. Cutting bones increases 

the possibility of contamination.

Collect teeth in the following order:

Nonrestored molar.

Nonrestored premolar.

Nonrestored canine.

Nonrestored front tooth.

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2.

3.

4.
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Handbook of Forensic Services 2007

Restored molar.

Restored premolar.

Restored canine.

Restored front tooth.

Place tissue samples in a clean, airtight 

plastic container without formalin or 

formaldehyde. Place teeth and bone 

samples in clean paper or an envelope with 

sealed corners.

Freeze the evidence, place in Styrofoam 

containers, and ship overnight on dry ice.

Preserving DNA Evidence–—Long-Term 

Storage

Blood/saliva (reference samples).

Refrigerate, do not freeze, liquid blood 

samples.

Store refrigerated, frozen (if dried), or 

at room temperature, away from light 

and humidity.

Blood/semen (evidence samples).

5.

6.

7.

8.

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Handbook of Forensic Services 2007

Store refrigerated, frozen, or at room 

temperature, away from light and 

humidity.

DNA tubes/tissue samples, etc.

Store refrigerated or frozen, 

if possible. 

It is recommended that these samples be 

stored in a refrigerator/freezer and 

isolated from evidence that has not 

been examined.

Back to the top

Electronic Device Examinations

Commercial Electronic Devices 

Examinations of commercial electronic devices—

including personal digital assistants (PDAs), 

cellular telephones, pagers, and global positioning 

systems (GPSs)—can extract user- or ownerentered data and other information. In some 

cases, it is necessary to disassemble the devices 

during examination.

Interception-of-Communication Devices

Interception-of-communication (IOC) devices are 

used to unlawfully intercept oral or wire 

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Handbook of Forensic Services 2007

communications. The devices consist of radiofrequency transmitters and receivers. 

Examinations are conducted to identify operating 

characteristics (frequency of operation, range of 

operation). In some cases, it is necessary to 

disassemble the devices during examination.

Other Electronic Devices and Circuits

Examinations on other electronic devices and 

circuitry—including facsimile machines, stun guns, 

and bomb detonators—can extract user- or 

owner-entered data, stored data, and other 

information. The examinations can identify 

operating characteristics and modifications made 

to the devices. In some cases, it is necessary to 

disassemble the devices and/or circuits during 

examination.

Questions concerning electronic device 

examinations should be directed to 

703-985-2400. Questions concerning shipping 

electronic device evidence should be directed 

to 703-985-1388. FBI entities may refer to the 

Operational Technology Division/Digital 

Evidence Section web page on the FBI intranet 

for additional information regarding evidence 

submission.
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Handbook of Forensic Services 2007

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Label the outer container “FRAGILE, 

SENSITIVE ELECTRONIC EQUIPMENT” 

and “KEEP AWAY FROM MAGNETS OR 

MAGNETIC FIELDS.”

Address the outer container as follows: 

FORENSIC PROGRAM

BUILDING 27958A 

ENGINEERING RESEARCH FACILITY

FEDERAL BUREAU OF INVESTIGATION

QUANTICO VA 22135

Back to the top

Explosives Examinations

Evidence resulting from an apparent explosion 

and/or recovery of an explosive device can be 

examined. Examinations are based on the 

premise that components and accessories used 

to construct the devices survive the explosion, 

although disfigured. The examinations can 

accomplish the following:

Identify the components used to construct 

the device, such as switches, batteries, 

detonators, tapes, wires, and fusing systems.

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Handbook of Forensic Services 2007

Identify the explosive main charge.

Determine the construction characteristics.

Determine the manner in which the device 

functioned or was designed or intended to 

function.

Determine the specific assembly techniques 

employed by the builder(s) of the device.

Preserve the trace evidence potentially 

present in the devices so that it is not 

destroyed or damaged during the 

examinations.

Call the Laboratory at 703-632-7626 each time 

an explosive device or a related explosive item 

needs to be shipped. The communication 

accompanying the evidence must reference the 

telephone conversation accepting the evidence. 

Questions concerning explosives evidence 

should be directed to 703-632-7626.

Explosives are hazardous materials and must 

be handled only by qualified public safety 

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Handbook of Forensic Services 2007

personnel, military explosives ordnance 

disposal personnel, or certified bomb 

technicians. Special packaging is required, 

and the amount to be shipped is regulated. An 

FD-861 form (Mail/Package Alert) is required 

for shipping bomb components to the FBI 

Laboratory.

Back to the top

Explosives Residue Examinations

Instrumental analyses of explosives residue can 

determine whether substances are high-explosive, 

low-explosive, or incendiary mixtures; whether the 

composition of the substances is consistent with 

known explosives products; and the type of 

explosives. Explosives residue can be deposited 

on metal, plastic, wood, paper, glass, cloth, and 

other surfaces. Residue may be deposited after 

handling, storing, or initiating an explosive.

Questions concerning explosives residue 

evidence should be directed to 703-632-7626. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Some explosives residue is water-soluble and 

must be protected from moisture. Other 

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Handbook of Forensic Services 2007

residue evaporates quickly and must be 

collected as soon as possible in airtight 

containers such as metal cans, glass jars, or 

heat-sealed or resealable nylon or Mylar 

bags. Ziplock storage bags are not suitable for 

shipping or storing explosives residue 

evidence. Do not fill the containers to the top. 

Pack to prevent breakage.

Collect and preserve control samples from the 

blast site.

Extreme care must be taken to avoid 

contaminating explosives residue evidence.

Never store or ship explosives residue 

evidence with bulk explosive materials.

Never store or ship explosives residue evidence 

from a crime scene with evidence from a search 

site.

Back to the top

FBI Disaster Squad

Assists in printing the deceased at disaster 

scenes.

Assists in collecting antemortem fingerprints 

of victims.

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Handbook of Forensic Services 2007

Assists in identifying friction ridge skin of the 

deceased.

Deployment of the FBI’s Disaster Squad 

requires consent from the disaster scene 

coroner or medical examiner, a ranking law 

enforcement or government official, a 

representative of the National Transportation 

Safety Board, or a representative of the U.S. 

Department of State. 

Requests for assistance must be made 

through the nearest FBI field office or the 

FBI’s Strategic Information and Operations 

Center at 202-323-3300. 

Back to the top

Feather Examinations

Feather examinations can determine bird species 

and can compare feathers found on clothing, 

vehicles, and other objects with feathers from the 

crime scene.

Questions concerning feather evidence 

should be directed to 703-632-8449. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

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Handbook of Forensic Services 2007

Submit feathers in heat-sealed or resealable 

plastic bags or paper bags.

Back to the top

Firearm Examinations

Firearms

Firearm examinations can determine the general 

condition of a firearm and whether the firearm is 

mechanically functional or in a condition that could 

contribute to an unintentional discharge. Triggerpull examinations can determine the amount of 

pressure necessary to release the hammer or 

firing pin of a firearm. Examinations can determine 

whether a firearm was altered to fire in the fullautomatic mode. Obliterated and/or altered 

firearm serial numbers sometimes can be 

restored. Firearms can be test-fired to obtain 

known specimens for comparison with evidence 

ammunition components, such as bullets, 

cartridge cases, and shotshell casings. 

Comparisons of suspect firearms can be made 

with firearms depicted in surveillance images, 

possibly resulting in an “association” conclusion. 

Photogrammetry can determine the length of the 

weapon(s) used by the subject(s) depicted in the 

surveillance images. See Image Analysis 

Examinations.

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Bullets

Fired bullets can be examined to determine 

general rifling characteristics such as caliber, 

physical features of the rifling impressions, and 

the manufacturer of the bullets. The microscopic 

characteristics on evidence bullets can be 

compared with test-fired bullets from a suspect 

firearm to determine whether the evidence bullet 

was fired from that firearm.

Cartridge Cases or Shotshell Casings

Cartridge-case or shotshell-casing examinations 

can determine the caliber or gauge, the 

manufacturer, and whether there are marks of 

value for comparison. The images of questioned 

cartridge cases and shotshell casings can be 

scanned into the National Integrated Ballistic 

Information Network (NIBIN) to compare with 

evidence from other shooting incidents. The 

microscopic characteristics of evidence cartridge 

cases and shotshell casings can be examined to 

determine whether they were fired from a specific 

firearm.

Shot Pellets, Buckshot, or Slugs

Examinations of shot pellets, buckshot, or slugs 

can determine the size of the shot, the gauge of 

the slug, and the manufacturer.
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Wadding

Examinations of wadding components can 

determine the gauge and the manufacturer.

Unfired Cartridges or Shotshells

Examinations of unfired cartridges or shotshells 

can determine the caliber or gauge and whether 

there are marks of value for comparison. 

Examinations also can determine whether the 

ammunition was loaded in and extracted from a 

specific firearm. Unfired and fired cartridges or 

shotshells can be associated through 

manufacturing marks.

Gunshot Residue on Victim’s Clothing

The deposition of gunshot residue on evidence 

such as clothing varies with the distance from the 

muzzle of the firearm to the target. Patterns of 

gunshot residue can be duplicated using a 

questioned firearm-and-ammunition combination 

fired into test materials at known distances. These 

patterns serve as a basis for estimating muzzleto-garment distances.

Gun Parts

Examinations of gun parts can determine the 

caliber and model of the gun from which the parts 

originated.
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Silencers

Muzzle attachments can reduce the noise of a 

firearm by suppressing sound during firing. Testing 

can determine whether a muzzle attachment can 

be classified as a silencer based on a measurable 

sound-reduction capability.

Questions concerning firearm evidence 

should be directed to 703-632-8442. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

All firearms must be unloaded.

The firearm should be submitted. If the firearm 

cannot be submitted, call 703-632-8442 for 

instructions.

The firearm must be handled minimally to 

avoid loss or destruction of evidence. Do not 

allow objects to enter or contact the firearm’s 

barrel, chamber, or other operating surface.

Firearms and ammunition components such 

as bullets, cartridge cases, and shotshell 

casings can be sent via Registered Mail 

through the U.S. Postal Service. Evidence 

must be packaged separately and identified 

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by date, time, location, collector’s name, case 

number, and evidence number.

U.S. Department of Transportation 

regulations and the following guidelines must 

be followed when shipping live 

ammunition:

Package and ship ammunition separately 

from firearm(s).

The outside of the container must be 

labeled “ORM-D, CARTRIDGES, SMALL 

ARMS.”

The Declaration of Dangerous Goods 

must include the number of package(s) 

and the gross weight in grams of the 

completed package(s). 

Do not mark the firearm. Firearms must be 

identified with a tag containing the caliber, 

make, model, and serial number. The date, 

time, name(s) of the owner(s), location, 

collector’s name, case number, and evidence 

number must be on the container.

Do not mark bullets, cartridges and cartridge 

cases, shotshells and shotshell casings, or 

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other firearm-related evidence. The date, 

time, location, collector’s name, case number, 

and evidence number must be on the 

container.

Clothing submitted for gunshot residue 

examination must be carefully handled, airdried, and wrapped separately in paper. 

Clothing with blood must be air-dried and 

labeled “BIOHAZARD” on the inner and outer 

containers. The date, time, location, collector’s 

name, case number, and evidence number 

must be on the container.

Back to the top

Forensic Facial Imaging

Visual information specialists provide composite 

drawings, two- and three-dimensional facial 

reconstructions from skeletal remains, facial age 

progressions, postmortem reconstructions, and 

digital photographic manipulations and retouches. 

Interviews required to prepare composite 

drawings may be conducted either by having a 

visual information specialist travel to the field or by 

using video teleconferencing.

For facial comparisons between known and 

questioned subjects, see Image Analysis 

Examinations.

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Questions concerning forensic facial imaging 

should be directed to 703-632-8194.

Back to the top

Glass Examinations

Glass comparison examinations can determine 

whether particles of glass originated from a 

broken source of glass. Glass fracture 

examinations can determine the direction and 

type of the breaking force and the sequencing of 

shots.

Questions concerning glass evidence should 

be directed to 703-632-8449. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Comparison

Submit samples of glass from each broken 

window or source in leakproof containers such 

as film canisters or plastic pill bottles. Do not 

use paper or glass containers.

Submit samples of laminated glass (e.g., 

windshield) from each side of the glass. Label 

the samples “INSIDE” and “OUTSIDE” and 

package separately in leakproof containers 

such as film canisters or plastic pill bottles. Do 

not use paper or glass containers.

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Submit the air-dried clothing of the victim(s) 

and suspect(s). Package each item separately 

in a paper bag.

Search for particles in the hair, skin, and 

wounds of the victim(s) and suspect(s). 

Submit particles in leakproof containers such 

as film canisters or plastic pill bottles. Do not 

use paper or glass containers.

Search for particles in vehicles by vacuuming 

each section of the vehicle separately. Do not 

use tape for recovering glass particles. Submit 

vacuum sweepings in leakproof containers. 

Do not use paper or glass containers.

Ship known and questioned debris separately 

to avoid contamination.

Do not process evidence for latent prints.

Fracture 

Label the sides of the glass in the frame 

(“INSIDE” and “OUTSIDE”). Label the glass 

where it was removed in the frame (“TOP,” 

“BOTTOM,” “LEFT,” and “RIGHT”).

Submit all glass pieces so that the pieces can 

be fit together to identify the radial cracks near 

and at the point(s) of impact and to increase 

the probability of matching edges. Pack all 

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glass separately and securely to avoid shifting 

and breaking during shipping.

Submit the entire piece of laminated glass, if 

possible. Secure the glass between sheets of 

plywood or sturdy cardboard. Do not place 

any objects into the impact area. 

Do not process evidence for latent prints. 

Back to the top

Hair and Fiber Examinations

Hair

Hair examinations can determine whether hairs 

are animal or human. Race, body area, method of 

removal, damage, and alteration (e.g., bleaching 

or dyeing) can be determined from human-hair 

analysis. Examinations can associate a hair to a 

person on the basis of microscopic characteristics 

in the hair but cannot provide absolute personal 

identification. Hairs that are associated will be 

submitted for mitochondrial DNA analysis. 

Fibers

Fiber examinations can identify the type of fiber, 

such as animal (wool), vegetable (cotton), mineral 

(glass), and synthetic (manufactured). Questioned 

fibers can be compared with fibers from the 

clothing, carpeting, and other textiles of victim(s) 

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and suspect(s). A questioned piece of fabric can 

be matched physically to known fabric. Fabric 

composition, construction, and color can be 

compared, and impressions on and from fabric 

can be examined. Label searches can determine 

clothing manufacturer information.

Questions concerning hair and fiber evidence 

should be directed to 703-632-8449. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

For known hair samples, collect at least 25 

hairs from different parts of the head and/or 

pubic region. Comb and pull out the hairs. 

Submit hairs in clean paper or an envelope 

with sealed corners.

When possible, submit the entire garment or 

textile. Submit fibers in clean paper or an 

envelope with sealed corners.

Back to the top

Image Analysis Examinations

Image analysis examinations are conducted by 

the FBI’s Operational Technology Division (OTD), 

Digital Evidence Laboratory (DEL), Forensic 

Audio, Video, and Image Analysis Unit (FAVIAU). 

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The OTD DEL has different acceptance criteria 

and a different physical address than the FBI 

Laboratory, as described below.

Photographic Comparisons

Examinations of film, negatives, digital images, 

photographic prints, and video recordings, 

including surveillance images, involve 

comparisons of subject(s) or object(s) depicted in 

questioned images with those in known images. 

Subject(s) or object(s) also can be compared 

between multiple questioned images. Subject 

comparisons include facial comparisons or can be 

made between like body parts, such as hands or 

ears. Examples of objects that can be compared 

include clothing, firearms, and vehicles. 

Photogrammetry

Physical dimensions can be derived from images 

through the use of geometric formulas or on-site 

comparison. For on-site comparisons, examiners 

enter the scene and place a height chart at the 

location of the subject(s) or object(s) of interest. 

Examples of photogrammetry include determining 

the height of a bank robbery subject(s) and the 

length of the weapon(s) used by the subject(s) 

depicted in surveillance images.
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Authenticity and Image-Manipulation 

Detection

Photographic evidence—including film, video, and 

digital images—can be examined to determine 

whether the image is the result of a composite, an 

alteration, or a copy.

Location, Time, and Date

Examinations of photographic evidence can 

determine the location, time, and date that an 

image was taken.

Source and Age

Photographic products, including film and prints, 

can be dated, and the source can be established 

by examining manufacturing characteristics. This 

can establish the time frame during which a 

photograph was taken.

Cameras

Cameras, both film and digital, seized as evidence 

can be compared with images to determine 

whether a specific camera captured a specific 

image. Similarly, digital video cameras can be 

compared with video clips. 

Video

Still images can be produced from video clips, 

enhanced and enlarged, and used in courtroom 

presentations.
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Automobile Make and Model Identification

Vehicles depicted in surveillance images can be 

compared with the National Automotive Image File 

to determine make and model.

Child Pornography Examinations

Seized images of child pornography should be 

searched for known victims by checking with the 

National Center for Missing and Exploited 

Children and the Innocent Images National 

Initiative. The images also can be compared with 

images in the Child Exploitation and Obscenity 

Reference File to identify the source of the 

images. Video clips can be examined to determine 

if any of the people and scenes depicted in the 

video clips are also recorded as still images in the 

reference file. Video clips and still images also can 

be examined to determine if they depict 

recordings or images of real people and events or 

whether they represent computer-generated 

subjects and events.

Questions concerning image analysis 

examinations should be directed to 703-985-

1393. Questions concerning image analysis 

evidence should be directed to 703-985-1388.

Image analysis examinations may not be 

submitted directly from entities outside the FBI. 
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State, local, or international agency cases must 

be submitted by the FBI field office servicing the 

area and must meet one of the following two 

criteria: 1) the state, local, or international case 

has a nexus to an ongoing FBI investigation or 

2) the FBI division head deems that the case is of 

enough regional importance to merit the 

dedication of federal resources to the state, local, 

or international case. These criteria shall be met 

with a written statement from the division head 

(Special Agent in Charge). FBI entities may submit 

cases directly.

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Write-protect the original media. Never use 

the Pause operation when viewing original 

video recordings.

Submit original evidence (e.g., negatives, 

videotape, CD) whenever possible because it 

contains the greatest level of detail. If the 

original media is unavailable, submit firstgeneration photographic prints, videotapes, or 

digital files of the evidence, being careful not 

to introduce further compression.

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Process all film prior to submitting. Bank 

surveillance film should be processed by the 

bank’s security company according to 

manufacturer specifications.

When requesting forensic examinations based 

on video images, queue the original videotape 

to the approximate time of the pertinent area. 

State in a communication the date and time of 

the pertinent area and use the date-time 

stamp on the images or the counter indicator 

(set from the beginning of the tape at 000). If 

prints from the relevant frames are available, 

submit them for reference.

Arrest or known photographs of suspect(s) for 

comparison with questioned images must 

depict the suspect(s) from many angles 

similar to the questioned images. If a facial 

comparison is requested, ensure that the face 

or head of the suspect(s) fills more than half 

the frame. If questioned images show tattoos 

or marks, include photographs of the same 

areas of the body on the known suspect(s).

When taking known photographs for 

comparison with questioned images, use 

35 mm film or digital equivalent (at highest 

resolution settings to minimize image 

compression).

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Do not mark or cut items submitted for 

comparison (e.g., clothing or firearms) where 

they are visible in the questioned images.

Physical items such as clothing and firearms 

must be submitted to the Laboratory for other 

examinations such as trace evidence, 

ballistic, or fingerprint analyses before they 

are submitted for image comparison.

If photogrammetry is requested, include the 

dimensions of the scene to the nearest eighth 

of an inch and include a diagram or print from 

the relevant images indicating the location of 

the measurements. Include one diagram or 

print for every angle used in the scene. Do not 

touch or move the surveillance cameras.

Submissions for comparison with the Child 

Exploitation and Obscenity Reference File 

must be limited to no more than 30 images. 

Call 703-985-1393 for specific instructions.

When submitting such evidence as a 

videotape or data card, label the outer 

container “FRAGILE, SENSITIVE 

ELECTRONIC EQUIPMENT” or “FRAGILE, 

SENSITIVE AUDIO/VIDEO MEDIA” and 

“KEEP AWAY FROM MAGNETS OR 

MAGNETIC FIELDS.”

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Address the outer container as follows: 

FORENSIC PROGRAM

BUILDING 27958A 

ENGINEERING RESEARCH FACILITY

FEDERAL BUREAU OF INVESTIGATION

QUANTICO VA 22135

Back to the top

Ink Examinations

Examining inked writing in conjunction with other 

techniques (e.g., handwriting analysis, watermark 

identification) can provide details regarding 

document preparation. The composition of writing 

inks varies with the type of writing instrument 

(e.g., ballpoint pen, fountain pen, porous-tip pen) 

and the date of the ink manufacture. In general, 

inks are composed of dyes in solvents and other 

materials that impart selected characteristics. Ink 

analysis usually is limited to comparisons of the 

organic dye components. When ink formulations 

are the same, it is not possible to determine 

whether the ink originated from the same source 

to the exclusion of others. Examinations cannot 

determine how long ink has been on a document.

Questions concerning ink evidence should be 

directed to 703-632-8441. Follow the evidence 

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submission directions, including Requesting 

Evidence Examinations and Packaging and 

Shipping Evidence.

Pack ink evidence separately from any 

document or surface with ink marks. 

Back to the top

Latent Print Examinations

Case Acceptance Policy

Because of the increasing casework demands of 

the FBI’s primary mission, protecting the United 

States from terrorist attacks, the FBI Laboratory 

will no longer accept routine cases from state and 

local agencies in which latent print examination 

services may be obtained from within the 

submitting agency’s system. The future 

acceptance of any state and local cases generally 

will be based on the submitting agency’s lack of 

access to the same techniques or services 

provided by the FBI Laboratory, the unusual 

technical nature of the case, or the circumstances 

surrounding the case, e.g., cases of a high-profile 

nature or cases that also involve FBI field offices. 

Developing Latent Prints at Crime Scenes

The Laboratory is the best place to develop latent 

prints; however, it is sometimes necessary to 

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develop latent prints at crime scenes. Caution 

should be taken to prevent destroying latent 

prints. The following measures ensure that crime 

scene latent prints are protected:

Photograph latent prints prior to any 

processing.

Examine all evidence visually and with a laser 

or an alternate light source before using any 

other latent print development process.

Photograph latent prints developed with 

fingerprint powders before lifting them.

Black, gray, or white powder can be applied to 

a surface with a variety of style of brushes. 

The color of the powder should contrast with 

the color of the surface (e.g., black for light 

surfaces and gray or white for dark surfaces).

Use a short-hair brush or cotton to remove 

excess powder. Use caution when powdering. 

Avoid overbrushing latent prints and losing 

clarity.

Use transparent tape or black-and-white 

rubber lifts to lift latent prints. 

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When transparent tape is used, the color of 

the backing card should contrast with the color 

of the powders (e.g., white backing card for 

black powder).

When using latent print development 

processes, refer to the manufacturer’s 

instructions and the Material Safety Data 

Sheets. Use personal protective equipment 

(e.g., safety glasses, masks, gloves, smocks). 

The Processing Guide for Developing Latent 

Prints is a comprehensive guide to latent print 

processes and protocols. Refer to this 

publication to ensure that proper processes 

are applied in the recommended order. 

Following this guide will maximize the 

potential to develop latent prints and will 

preserve evidence if other forensic 

examinations are required. The guide is 

available at http://www.fbi.gov/hq/lab/fsc/

backissu/jan2001/lpu.pdf. Law enforcement 

personnel may request the Processing Guide 

for Developing Latent Prints in field-manual 

format by faxing a request on agency 

letterhead to 703-632-8374.

Photographing Latent Prints

Use a tripod and cable release when 

photographing latent prints.

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Use a 35 mm or medium-format camera with 

a macro lens capable of half-size to full-size 

reproduction.

Photograph latent prints at each step in the 

processing sequence before moving to the 

next process.

Photograph latent prints developed with 

fingerprint powders before lifting them.

When possible, use ISO 400 film. Set the lens 

f-stop to the smallest possible aperture while 

using the camera meter to adjust the camera’s 

shutter speed to obtain proper exposure.

Take three exposures of each latent print by 

bracketing:

Original exposure.

One-stop underexposed image.

One-stop overexposed image.

Photograph latent prints individually. This 

ensures that the target latent print is in focus.

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For reference purposes, photograph latent 

prints close to one another in one frame, if 

possible.

Fill the frame completely.

Photograph latent prints with an identification 

label that includes a scale, reference number, 

date, collector’s initials, and location of the 

latent prints. The identification label should be 

placed on the same plane as the latent prints.

Maintain a photographic log that records each 

shot, reference number, date, collector’s 

initials, location of prints, and other pertinent 

information.

Questions concerning latent print evidence 

should be directed to 703-632-8443. Follow the 

evidence submission directions, including

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Stabilize the evidence to avoid movement or 

friction during shipping. 

Place nonporous evidence (e.g., nonabsorbent, hard surfaces) in separate protective 

coverings such as thick transparent envelopes 

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Handbook of Forensic Services 2007

(glassine), or suspend in a container so that 

there is minimal surface contact. Friction will 

destroy latent prints on this type of surface.

Place porous evidence (e.g., paper, 

cardboard) in separate protective coverings. 

Friction generally will not destroy latent prints 

on this type of surface. 

Submit known fingerprints and palm prints of 

everyone who may have handled the 

evidence, including suspects, victims, those 

who had legitimate access, and investigative 

personnel. All fingerprint cards must include 

pertinent biographical and/or demographic 

information.

Palm prints should be taken on only one side 

of a separate card, not on the reverse side of 

a fingerprint card or on the reverse side of a 

card that has a recorded impression on the 

other side.

Fingerprint cards and major-case prints 

should include, at a minimum, the name of the 

person printed, the name of the person 

recording the prints, the date, the caseidentification number, and a brief statement of 

facts relating to the case. The fingerprint card 

should bear an arrest offense. 

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The notation “elimination prints” should be 

included if the person printed is not a suspect.

When known prints are submitted separately 

from evidence, reference previous 

communications and case-identifying 

numbers and other pertinent information.

Submitting Latent and Intentionally Recorded 

Print Images in Digital Format

Digital images, including digital photographs, of 

latent and intentionally recorded prints should 

include a scale or other measurable item. If a 

search of the Integrated Automated Fingerprint 

Identification System (IAFIS) is requested, a scale 

or other measurable item is mandatory.

Digital images, including digital photographs, must 

meet the following requirements:

Documentation of the image source (e.g., 

window, door frame).

Documentation of the capture device (e.g., 

flatbed scanner, digital camera).

Documentation indicating the image is an 

original capture. 

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File properties for latent images consisting of:

A file format without compression or with 

lossless compression (e.g., RAW, TIFF).

A minimum of 8 bits for grayscale images 

and 24 bits for color images.

A resolution that meets or exceeds 1000 

pixels per inch (PPI) when calibrated to 

actual size (1:1).

File properties for intentionally recorded prints 

consisting of:

A file format without compression, with 

lossless compression (e.g., RAW, TIFF), 

or with Wavelet Scalar Quantization 

(WSQ) compression saved at a maximum 

of 15:1.

A minimum of 8 bits for grayscale images 

and 24 bits for color images. 

A resolution that meets or exceeds 500 

PPI when calibrated to actual size (1:1).

Latent prints submitted as facsimiles or 

photocopies will not be examined in the FBI 

Laboratory.

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Intentionally recorded prints submitted as 

facsimiles will not be examined in the FBI 

Laboratory, except when the known prints will be 

searched against IAFIS in order to obtain FBI file 

prints.

Submitting Hands or Fingers of an Unknown 

Deceased

Pack each hand or finger in a separate 

unbreakable, watertight, and airtight container.

Label each container (e.g., “RIGHT HAND,” 

“RIGHT THUMB,” “RIGHT INDEX”). 

Ship the remains in the condition in which 

they were found (e.g., in water, frozen, dried) 

by the most expeditious means.

Provide a complete physical description of the 

deceased, if possible. 

Label the outer container “KEEP IN A COOL, 

DRY PLACE,” “REFRIGERATE ON 

ARRIVAL,” and “BIOHAZARD.”

All human remains will be returned to the 

contributor.

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Address the outer container as follows:

EVIDENCE CONTROL UNIT

LABORATORY DIVISION

FEDERAL BUREAU OF INVESTIGATION

2501 INVESTIGATION PARKWAY

QUANTICO VA 22135

Legible, complete ten-print fingerprint cards 

not related to an ongoing Laboratory 

investigation should be sent to the FBI’s 

Criminal Justice Information Services Division.

Address the outer container as follows:

CRIMINAL JUSTICE INFORMATION 

 SERVICES DIVISION

FEDERAL BUREAU OF INVESTIGATION

1000 CUSTER HOLLOW ROAD

CLARKSBURG WV 26306

Questions concerning ten-print fingerprint 

cards should be directed to 304-625-2360.

Back to the top

Lubricant Examinations

Lubricants encompass a range of substances, 

including petroleum products, natural fatty ester 

oils, and polyalkylene glycol oils. Automotive fluids 

(e.g., engine oil, brake fluid), certain cosmetics 

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(e.g., bath oils, lotions), and some polishes 

contain lubricants. Lubricant examinations may 

also be conducted in sexual assault, vehicular 

homicide, or heavy-equipment sabotage cases.

Questions concerning lubricant evidence 

should be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Submit entire items (e.g., clothing) when 

possible. Air-dry the evidence, and package 

separately in paper bags.

Absorb suspected lubricants onto a clean 

cotton cloth or swab. Leave a portion of the 

cloth or swab unstained as a control. Air-dry 

the swab and pack in a heat-sealed or 

resealable plastic bag. 

Submit suspected sources of lubricants for 

comparison examinations.

Package lubricants separately in leakproof 

containers.

Back to the top

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Metallurgy Examinations

Comparison

Comparative examinations can determine whether 

two metals or metallic objects came from the 

same source or from each other. Metal 

comparisons can identify various surface and 

microstructural characteristics—including 

fractured areas, accidental damage, and 

fabrication marks—to determine whether the 

objects share a common origin. Moreover, the 

manufacturing methods used to produce an object 

can be determined. These manufacturing 

techniques can include casting, forging, hot and 

cold rolling, extrusion, drawing, swaging, milling, 

grinding, spinning, blanking, ironing, deep 

drawing, and others. Examinations can determine 

mechanical properties, such as the response of a 

metal to an applied force or load. Examinations 

also can determine chemical composition, 

including alloying and trace elements.

Broken or Mechanically Damaged Metal

The causes of failure or damage—such as the 

application of stress exceeding the tensile 

strength or yield limit of the metal; a material or 

manufacturing defect; or corrosion, cracking, or 

excessive service usage (fatigue)—can be 
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Handbook of Forensic Services 2007

determined. The magnitude of the force or load 

that caused the failure, how the force or load was 

transmitted to the metal, and the direction it was 

transmitted also can be determined.

Burned, Heated, or Melted Metal

Examinations can determine the approximate 

temperature to which a metal was exposed, the 

nature of the heat source, and whether a metal 

was in an electrical short-circuit situation.

Cut or Severed Metal

Examinations can determine the method by which 

a metal was severed, such as sawing, shearing, 

milling, turning, or thermal cutting. The nature of 

the thermal source (e.g., burner bar, electric arc 

welder) used can sometimes be determined.

Metal Fragments

Examinations can determine how metal fragments 

were formed. If fragments were formed by 

impulsive (short-duration, high strain rate) loading, 

an examination can determine whether an 

explosive was detonated and the magnitude of the 

detonation velocity. The nature of the object that 

was the source of the fragments often can be 

determined as well.
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Specification Fraud and Noncompliant 

Materials

Metallurgical testing of materials can determine 

whether inferior components were substituted in 

contracting frauds. The composition and 

mechanical properties of materials can be 

examined to determine if the components meet 

contractual obligations or appropriate regulatory 

codes. Precious-metal content also can be 

determined.

Lamp Bulbs

Examinations can determine whether a lamp bulb 

was incandescent when its glass envelope was 

broken. Determinations also can be made as to 

whether a lamp bulb was incandescent when it 

was subjected to an impact force such as a 

vehicular collision. Such determinations can be 

made even if the glass was broken by the impact.

Watches, Clocks, and Timers

The conditions causing a watch, clock, timer, or 

other mechanism to stop or malfunction and 

whether the time displayed represents a.m. or 

p.m. (calendar-type timing mechanisms only) can 

be determined. The on/off condition of appliance 

timers damaged by a fire or explosion often can 

be determined.
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Objects with Questioned Internal Components

X-ray radiography can nondestructively reveal the 

interior construction and the presence or absence 

of defects, cavities, or foreign materials. The 

position of on/off switches and other mechanical 

components can be determined.

Questions concerning metallurgy evidence 

should be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Back to the top

National Missing Person DNA Database 

Program Examinations

The National Missing Person DNA Database 

(NMPDD) Program is supported by both the DNA 

Analysis Unit I (DNAUI) and DNA Analysis Unit II 

(DNAUII). Nuclear DNA examinations are 

conducted in the DNAUI and mitochondrial DNA 

examinations are conducted in the DNAUII to 

support the NMPDD Program. Each unit has an 

NMPDD Program Manager who is available to 

answer any questions regarding case submission 

(contact information is listed below). Local, state, 

and federal law enforcement missing-person 

cases can be submitted directly to the FBI 

Laboratory or through the FBI field offices or 

resident agencies. All agencies must contact one 
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of the FBI Laboratory’s NMPDD Program 

Managers before submitting samples. The 

submitting agency must have the necessary 

information and completed forms for sample 

submission. The FBI will perform mitochondrial 

DNA and nuclear DNA (STR) analyses on 

samples.

All samples submitted to the FBI Laboratory must 

have an incoming letter describing the samples 

submitted. A copy of the anthropology, odontology 

(dental), medical examiner and/or coroner, and 

law enforcement reports must be included with 

unidentified human remains samples submitted.

Contact either of the NMPDD Program Managers 

prior to submitting samples or for questions 

concerning samples.

Call 703-632-7586 for the DNAUI or 703-632-

7582 for the DNAUII.

For FBI (internal) e-mail, write to Eric Pokorak 

for the DNAUI or John E. Stewart for the 

DNAUII.

For Internet e-mail, write to eric.pokorak@

ic.fbi.gov for the DNAUI or john.stewart@

ic.fbi.gov for the DNAUII.

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Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Samples from Biological Relatives of Missing 

Persons

Samples must be sent with a Consent and 

Information Form for the National Missing 

Person DNA Database (FD-935 form). A copy 

of the law enforcement report should 

accompany the samples submitted.

Collect samples in the following order of 

preference:

Dried bloodstains.

Buccal (oral) swabs.

Dried Bloodstains

Use the blood-cell collection kits that are available 

in FBI field offices or by contacting the NMPDD 

Program Managers at 703-632-7582 or 

703-632-7586.

Buccal (Oral) Swabs

Use sterile, cotton-tipped applicator swabs to 

collect four buccal (oral) samples. Rub the 

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inside surfaces of the cheeks thoroughly (use 

two swabs on each side). 

Air-dry the swabs and place them back into 

the original packaging or an envelope with 

sealed corners. Do not use plastic containers.

Identify each sample with the date, time, 

subject’s name, location, collector’s name, 

and case number.

Buccal samples do not need to be 

refrigerated.

Samples from Unidentified Human Remains

Call the Laboratory prior to submitting bones, 

teeth, or tissue. The communication 

accompanying the evidence must reference the 

telephone conversation accepting the evidence. 

Skeletal Samples

Anthropological examinations can determine 

whether skeletal remains are human or animal. 

Race, sex, approximate height, and stature at 

death can be determined from human remains.

Pick up samples with gloved hands or clean 

forceps.

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Air-dry samples and place in paper bags.

Submit whole samples. Cutting skeletal 

samples increases the possibility of 

contamination. 

If possible, submit three samples. 

Submit skeletal samples with an anthropolog-

ical report, preferably from an anthropologist 

certified by the American Board of Forensic 

Anthropology, or a medical examiner’s/

coroner’s report.

Submit skeletal samples in the following order 

of preference: 

Femur.

Tibia.

Humerus.

Teeth, skull, and/or mandible.

Hand and foot bones.

Lower arm bone.

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Vertebrae.

Ribs.

Teeth

Personal identifications can be made by 

comparing teeth with dental records and X-rays.

Pick up teeth with gloved hands or clean 

forceps.

Air-dry teeth and place in paper bags.

Submit teeth with an odontological report, 

preferably from an odontologist certified by 

the American Board of Forensic Odontology, 

or a medical examiner’s/coroner’s report.

Submit teeth in the following order of 

preference:

Nonrestored molar.

Nonrestored premolar.

Nonrestored canine.

Nonrestored front tooth.

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Restored molar.

Restored premolar.

Restored canine.

Restored front tooth.

Tissue

Tissue samples usually will provide sufficient 

quantities of DNA for testing.

Pick up tissue with gloved hands or clean 

forceps.

Collect 1–2 cubic inches of red skeletal 

muscle.

Place tissue samples in a clean, airtight 

plastic container without formalin or 

formaldehyde and keep refrigerated or frozen.

Label the outer container “KEEP IN A COOL, 

DRY PLACE,” “REFRIGERATE ON 

ARRIVAL,” and “BIOHAZARD.”

Submit to the Laboratory as soon as possible.

Back to the top

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Paint Examinations

The layer structure of a questioned paint sample 

can be compared with a known source from a 

suspect. The sequence, relative thickness, color, 

texture, number, and chemical composition of 

each of the layers can be compared. 

The color, manufacturer, model, and model year 

of an automobile may be determined from a paint 

chip. Sourcing automotive paints is limited to 

factory-applied, original automotive paint.

Paint on safes, vaults, windowsills, and door 

frames can be transferred to and from tools. A 

comparison can be made between the paint from 

an object and the paint on a tool.

The Laboratory will not examine evidence to 

authenticate fine art or historical artifacts or to 

source spray paint or architectural paints.

Questions concerning paint evidence should 

be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Search the accident or crime scene and the 

personal effects of the victim(s) to locate paint 

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fragments. Paint fragments often are found in 

the clothing of the hit-and-run victim(s). 

Submit the clothing. Paints can be transferred 

from one car to another, from car to object, or 

from object to car during an accident or a 

crime.

Control paint chips must be collected from the 

suspected source of the evidentiary paint. 

Controls must be taken from an area close to, 

but not in, any damaged area. If no damage is 

obvious, controls should be taken from 

several areas of the suspect substrate. Each 

layer can be a point of comparison. Controls 

must have all of the layers of paint to the 

substrate. This can be accomplished by the 

following:

Section an area of the painted surface.

Cut a paint sample from the surface using 

a clean, sharp instrument.

Lift or pry loosely attached chips or 

dislodge the paint by gently hitting the 

opposite side of the painted surface.

Package paint specimens in leakproof 

containers such as vials or pillboxes. Do not 

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attach paint particles to adhesive tape. Do not 

use plastic bags, cotton, or envelopes to 

package paint specimens. 

Back to the top

Pepper-Spray or Pepper-Foam 

Examinations

Oleoresin capsicum is a resin in various peppers. 

It may be used in self-defense sprays or foams. 

Ultraviolet dye (orange) and/or tear gas also may 

be in the sprays or foams. Items can be analyzed 

for the presence of oleoresin capsicum, dye, or 

tear gas.

Questions concerning pepper-spray evidence 

should be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Submit entire items (e.g., clothing) when 

possible. Air-dry the evidence, and package 

separately in paper bags.

Moisten a clean cotton cloth or swab with 

isopropanol (rubbing alcohol), and wipe over 

the suspected sprays or foams. Prepare a 

second moistened cloth or swab as a control. 

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Air-dry the cloths or swabs and pack 

separately in heat-sealed or resealable plastic 

bags. 

Submit spray canisters when possible.

Refer to Hazardous Materials 

Transportation when submitting pepperspray canisters.

Back to the top

Pharmaceutical Examinations

Pharmaceutical examinations can identify 

constituents, active ingredients, quantity, and 

weight.

Questions concerning pharmaceutical 

evidence should be directed to 703-632-

8441. Follow the evidence submission 

directions, including Requesting Evidence 

Examinations and Packaging and Shipping 

Evidence.

List the names of the pharmaceuticals and 

information on their use.

If possible, submit pharmaceuticals in original 

containers. 

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Polymer Examinations

Polymer evidence typically consists of pieces of 

plastic or other manufactured materials. The 

source, use, or manufacturer of polymer evidence 

usually cannot be identified by compositional 

analysis.

Motor vehicle trim can be compared with plastic 

remaining on property struck in a hit-and-run case. 

The manufacturer, make, model, and model year 

of a vehicle can be determined if a manufacturer’s 

part number is on the trim.

Plastics in wire insulation and miscellaneous 

plastics such as buttons can be compared with 

known sources.

Questions concerning polymer evidence 

should be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

When a motor vehicle has been in an 

accident, fragments (e.g., plastic lens covers) 

can be left at the scene. These pieces can be 

physically reconstructed with the remnants of 

the fixture left on the car. Collect and package 

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the fragments carefully to keep the edges 

intact.

Search the accident or crime scene and 

personal effects of the victim(s) to locate 

plastic fragments. Submit fragments in 

leakproof containers such as film canisters or 

plastic pill bottles. Do not use cotton or paper 

containers.

Remove damaged suspect motor vehicle 

parts, and package separately in resealable 

plastic bags or boxes.

If possible, submit entire items (e.g., clothing) 

with potential or smeared polymeric transfers. 

Package separately in paper bags. If the 

entire item cannot be submitted, cut with a 

clean, sharp instrument a section where the 

transfer is suspected. Collect an unstained 

control sample. Pack to prevent stain removal 

by abrasive action during shipping. Pack in 

clean paper. Do not use plastic containers.

Back to the top

Product-Tampering Examinations

Product tampering is when a commercial product 

is intentionally distorted to harm someone or to 

extort money or other thing of value. Examples 

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range from drug tampering in medical 

environments, food adulteration in supermarkets, 

and the combination of tampering and altering in 

domestic settings. 

The Laboratory will not assess manufacturing 

quality control or product specifications in 

commercial products.

Questions concerning product-tampering 

evidence should be directed to 703-632-8441. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Submit control samples of the unadulterated 

product. 

Package and ship control and suspect 

samples separately to avoid contamination. 

Submit samples in leakproof containers such 

as film canisters or plastic pill bottles. Do not 

use paper or glass containers.

Use caution to prevent the destruction of 

latent prints.

Back to the top

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Questioned Document Examinations

Handwriting and Hand Printing

The examination and comparison of handwriting 

characteristics can determine the origin or 

authenticity of questioned writing, although not all 

handwriting is identifiable with a specific writer. 

Intent and such traits as age, sex, and personality 

cannot be determined from handwriting 

examinations. Some reasons for inconclusive 

results include:

Limited questioned and/or known writing.

Lack of sufficiently comparable known writing 

for comparison.

Lack of contemporaneous writing or lapse of 

time between execution of questioned and 

known writing.

Distortion or disguise in the questioned and/or 

known writing. 

Lack of sufficient identifying characteristics.

Submission of photocopied evidence instead 

of original evidence. 

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Procedures for Obtaining Known Writing 

Exemplars

The text, size of paper, space available for 

writing, writing instrument, and writing style 

(handwriting or hand printing) must be as 

close to the original writing as possible.

Give verbal or typewritten instructions 

concerning the text to be written. Do not give 

instructions on spelling, punctuation, or 

arrangement of writing.

All exemplars must be on separate pieces of 

paper.

The writer and witness must initial and date 

each page of writing.

Do not allow the writer to see the previous 

exemplars or the questioned writing. Remove 

each exemplar from the writer’s sight as soon 

as it is completed.

Numerous repetitions may be necessary to 

obtain naturally prepared writing. 

Obtain exemplars from the right and left 

hands.

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Obtain hand-printing exemplars in upper- and 

lowercase letters.

Obtain a sufficient quantity of exemplars to 

account for natural variation in the writing.

Obtain undictated writing such as business 

records, personal correspondence, and 

cancelled checks or other documents 

prepared during the normal course of 

business activity. 

Common Types of Nongenuine Signatures

Traced signatures are prepared by directly 

using a genuine signature as a template or 

pattern.

Simulated signatures are prepared by copying 

or drawing a genuine signature.

Freehand signatures are written in the forger’s 

normal handwriting with no attempt to copy 

another’s writing style. Therefore it may be 

possible to identify the writer(s) who prepared 

the signature(s).

Altered or Obliterated Writing

Documents can be examined for the presence of 

altered or obliterated writing, and the original 

writing may be deciphered.

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Typewriting

Questioned typewriting may be identified with the 

typewriter that produced it. This is most common 

when the typewriter is a typebar machine. The 

identification is based on individual characteristics 

that develop during the manufacturing process 

and through use and abuse of the typewriter.

Typewriters with interchangeable elements (e.g., 

ball, printwheel, or thimble) are less likely to be 

associated with questioned typewriting. However, 

these typing elements may be positively identified 

with specific texts by examining individual 

characteristics of the elements.

Comparison of questioned typewriting with 

reference standards can determine a possible 

make and model of the typewriter and/or the 

typewriter elements.

Carbon-film typewriter ribbons and correction 

ribbons retain readable text. These ribbons 

can be compared with questioned typewritten 

impressions. Generally, fabric ribbons cannot be 

read or identified.

Procedures for Obtaining Known Typewriting 

Exemplars

If the typewriter has a carbon-film ribbon or 

correction ribbon, remove it from the 

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typewriter and submit the ribbon to the 

Laboratory. Insert a new ribbon in the 

typewriter prior to obtaining exemplars.

If the typewriter has a fabric ribbon, remove it 

from the typewriter and put the typewriter in 

the stencil position. Place a sheet of carbon 

paper over a sheet of blank paper and insert 

both into the typewriter. Allow the typeface to 

strike the carbon paper. Submit the fabric 

ribbon and the exemplars typed on the carbon 

paper to the Laboratory.

Obtain two full word-for-word typed exemplars 

of the questioned text and two typed 

exemplars of the entire keyboard (all symbols, 

numbers, and upper- and lowercase letters).

Record the make, model, and serial number 

of the typewriter on the exemplars. Also 

record the date the exemplars were obtained 

and the name of the person who typed the 

exemplars.

Obtain the typewriter service and repair 

history, if available.

Normally it is not necessary to send the 

typewriter to the Laboratory; however, in some 

cases, the examiner will request the 

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typewriter. It must be packed securely to 

prevent damage during shipment. Typewriter 

elements (e.g., ball, printwheel, or thimble) 

also must be submitted to the Laboratory. 

Photocopies or Facsimiles

Photocopies or facsimiles of documents can be 

identified with the machine used to produce them 

if the exemplars and questioned documents are 

relatively contemporaneous. The possible make 

and model of the photocopier or facsimile machine 

sometimes can be determined.

Procedures for Obtaining Known Photocopy 

Exemplars

Obtain at least 10 exemplars without a 

document on the glass plate and with the 

cover down.

Obtain at least 10 exemplars without a 

document on the glass plate and with the 

cover up.

Obtain at least 10 exemplars with a document 

on the glass plate and the cover down.

Obtain at least 10 exemplars with a document 

through the automatic document feeder, if 

applicable.

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Record on each exemplar the date the 

exemplars were obtained, the name of the 

person who prepared the exemplars, and the 

conditions under which the exemplars were 

made.

Record the make, model, and serial number 

of the photocopier; information about the toner 

supplies and components; whether the paper 

supply is sheet- or roll-fed; and options such 

as color, reduction, enlargement, zoom, mask, 

trim, and editor board.

Do not store or ship photocopies in plastic 

envelopes. 

Graphic Arts (Commercial and Office 

Printing)

Printed documents can be associated with a 

common source or identified with known 

commercial printing paraphernalia such as 

artwork, negatives, and plates or office printing 

devices such as ink-jet or laser printers.

Paper

Torn edges can be compared. The paper 

manufacturer can be determined if a watermark is 

present. Paper can be examined for indented 

writing. Do not rub the indentations with a pencil. 

Do not add indentations by writing on top of the 

evidence.

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Burned or Charred Paper

Burned or charred documents (not completely 

reduced to ash) may be deciphered and stabilized. 

The document must be handled minimally. The 

document must be shipped in the container in 

which it was burned, in polyester film 

encapsulation, or between layers of cotton in a 

rigid container.

Age of a Document

The earliest date a document could have been 

prepared may be determined by examining various 

physical characteristics, including watermarks, 

indented writing, printing, typewriting, and inks.

Carbon Paper or Carbon-Film Ribbon

Used carbon paper or a carbon-film ribbon can be 

examined to disclose the content of the text.

Checkwriters

A checkwriter impression can be compared with a 

known source. Examining checkwriter impressions 

may determine the brand or model of the 

checkwriter.

Embossings and Seals

An embossed or seal impression can be compared 

with a known source. Submit the device to the 

Laboratory.
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Rubber Stamps

A rubber-stamp impression can be compared with 

a known source. Submit the rubber stamp to the 

Laboratory uncleaned.

Plastic Bags

Plastic bags (e.g., sandwich and garbage bags) 

can be compared with a roll or box of bags.

Anonymous Letter File

The Anonymous Letter File contains images of 

anonymous and/or threatening communications 

submitted to the Questioned Documents Unit for 

examination. This file can be searched in an 

attempt to associate text from a communication in 

one case with text from communications in other 

cases.

Bank Robbery Note File

The Bank Robbery Note File contains images of 

notes used in bank robberies. This file can be 

searched in an attempt to associate text from one 

bank robbery note with text from bank robbery 

notes in other cases.

Questions concerning documentary evidence 

should be directed to 703-632-8444. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.
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Documentary evidence must be preserved in 

the condition in which it was found. It must not 

be unnecessarily folded, torn, marked, soiled, 

stamped, or written on or handled excessively. 

Protect the evidence from inadvertent 

indented writing. Mark documents 

unobtrusively by writing the collector’s initials, 

date, and other information in pencil.

Whenever possible, submit the original 

evidence to the Laboratory. The lack of detail 

in photocopies makes examinations difficult 

and often will result in inconclusive opinions. 

Copies are sufficient for reference-file 

searches.

Do not store or ship photocopies in plastic 

envelopes. 

Back to the top

Rope and Cordage Examinations

A piece of rope or cord can be compared with 

a questioned rope or cord. The composition, 

construction, color, and diameter can be 

determined. If a tracer is present, the 

manufacturer can be determined.

Questions concerning rope and cordage 

evidence should be directed to 703-632-8449.

Follow the evidence submission directions, 

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including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Submit the entire rope or cord. If the rope or 

cord must be cut, specify which end was cut 

during evidence collection.

Label the known and questioned samples.

Handle the sections of rope or cord carefully 

to prevent loss of trace material or 

contamination.

Submit in heat-sealed or resealable plastic or 

paper bags. 

Back to the top

Safe-Insulation Examinations

Safe insulation can be compared to a known 

source. Examinations of safe insulation 

sometimes can determine the manufacturer.

Questions concerning safe-insulation 

evidence should be directed to 703-632-8449. 

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Collect safe-insulation samples from damaged 

areas.

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Safe insulation can adhere to people, clothing, 

tools, bags, and stolen items and can transfer 

to vehicles. If possible, submit the evidence to 

the Laboratory for examiners to remove the 

debris. Package each item of evidence in a 

separate paper bag. Do not process tools for 

latent prints.

Ship known and questioned debris separately 

to avoid contamination. Submit known and 

questioned debris in leakproof containers 

such as film canisters or plastic pill bottles. Do 

not use paper or glass containers. Pack to 

keep lumps intact.

Back to the top

Serial-Number Examinations

Obliterated serial or identification numbers—

including markings on metal, wood, plastic, and 

fiberglass—often are restorable. Comparisons can 

be made with suspect dies.

Questions concerning serial-number evidence 

should be directed to 703-632-8442. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

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For large objects, and if possible, remove the 

section containing the serial number and 

submit it to the Laboratory.

If it is not possible to remove the section 

containing the serial number, make a cast to 

submit to the Laboratory.

Use an acrylic-surface replica cast kit. Call 

the Laboratory at 703-632-8442 regarding 

the appropriate cast kit.

Different formulas are used in different 

temperatures. If possible, move the 

evidence to a warm area.

Casts will duplicate foreign material in the 

stamped characters. Clean the area 

before proceeding. Remove paint and dirt 

with a solvent such as acetone, gasoline, 

or paint remover. Use Naval Jelly to 

remove rust. Use a soft brush. Do not use 

a wire brush.

Build a dam around the stamped 

characters to retain the acrylic liquid 

while it hardens. Use a soft and pliable 

dam material such as modeling clay.

Ensure there are no voids in the dam.

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Following the instructions in the kit, mix 

the liquid and powder for one minute and 

pour the mixture into the dam.

The acrylic liquid will take 30 minutes to 

harden. Remove the cast when it is hard. 

If paint and rust are on the cast, make 

additional casts and submit the cleanest 

one to the Laboratory.

Indicate from where on the object (often a 

vehicle) the cast was taken.

Pack the cast to prevent breakage.

Back to the top

Shoe Print and Tire Tread Examinations

Shoe print or tire tread impressions are routinely 

left at crime scenes. These impressions are 

retained on surfaces in two- and threedimensional forms. Almost all impressions, 

including partial impressions, have value for 

forensic comparisons. The examination of detailed 

shoe print and tire tread impressions often results 

in the positive identification of the shoes of the 

suspect(s) or tire(s) from the vehicle(s) of the 

suspect(s).

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Photographing Shoe Print and Tire Tread 

Impressions

General crime scene photographs must be taken 

to relate the impressions to the crime scene. 

Examination-quality photographs then must be 

taken to obtain maximum detail for forensic 

examination and must include a scale. All 

impressions must be photographed using both 

methods.

General Crime Scene Photographs

General crime scene photographs of shoe print or 

tire tread impressions must include close-range 

and long-range photographs. ISO 400 color film 

should be used. The photographs must show the 

relationship of the impressions to the surrounding 

area. General crime scene photographs are not 

suitable for footwear or tire examinations.

Examination-Quality Photographs

Examination-quality photographs must be taken 

directly over the impressions using a tripod and 

lighting. A scale must be in every photograph. The 

purpose of these photographs is to produce a 

detailed negative that can be enlarged to natural 

size. Examination-quality photographs must be 

taken as follows:

Place a linear scale such as a ruler 

next to and on the same plane as the 

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impression. Place a label in the picture to 

correlate the impression with crime scene 

notes and general photographs.

Images should be taken using a 35 mm or 

medium-format film camera. Low-cost 

digital cameras do not provide sufficient 

image detail for examination-quality 

photographs. Use a manual-focus 

camera. If the shoe print is made from a 

colored substance (e.g., blood), color film 

may be preferable to black and white. In 

most ambient-light situations, use ISO 

100 film. Use ISO 200 or 400 film, if 

necessary.

Place the camera on a tripod and position 

it directly over the impression. Adjust the 

height of the camera, and if possible, use 

a normal lens (50 mm for a 35 mm 

camera). Fill the frame with the 

impression and scale. Position the 

camera so the film plane is parallel to the 

impression.

Set the f-stop on f/16 or f/22 for a greater 

depth of field.

Attach an electronic flash with a long 

extension cord to the camera.

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Block out bright ambient light with a 

sunscreen to maximize the light from the 

flash.

Focus on the bottom of the impression, 

not on the scale. Take an existing- or 

reflected-light photograph.

Position the flash at a very low angle 

(10–15 degrees) to the impression. This 

will enhance the detail of the impression. 

For consistent exposure, hold the flash at 

least 5–7 feet from the impression. Shoot 

several exposures, bracketing toward 

overexposure to obtain maximum image 

detail. Move the flash two or more angles 

to the impression.

Take the exposures, move the light to 

another position, adjust the sunscreen, 

and repeat Steps 7 and 8. 

Impressions in Snow

Impressions in snow are difficult to photograph 

because of lack of contrast. First, attempt to 

photograph the impressions as if in soil. To 

increase the contrast, lightly spray snow 

impressions with Snow Print Wax, a material used 

for casting snow impressions, or with colored 

spray paint. Hold the spray can at least 2–3 feet 

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from the impression so the force of the aerosol 

does not damage the impression. Direct a light 

application of spray at an angle of about 30–45 

degrees so the colored paint strikes only the high 

points of the impression. Highlighted impressions 

will absorb heat from the sun and must be 

shielded until photographed and cast to prevent 

melting.

Recovering the Original Evidence

Whenever possible, submit to the Laboratory the 

evidence bearing the original impression. If the 

evidence cannot be submitted to the Laboratory, 

use the following techniques to recover the 

evidence.

Casting Three-Dimensional Impressions

Casting a three-dimensional impression in soil, 

sand, or snow is necessary to capture detail for 

examination. Dental stone, with a compressive 

strength of 8,000 psi or greater, must be used for 

casting all impressions. The compressive strength 

is listed on the container along with the proper 

ratio of powder to water used for mixing. Dental 

stone is available through local dental supply 

houses. Colored dental stone is preferred.

Plaster of paris, modeling plasters, and dental 

plasters are not sufficiently hard, do not resist 

abrasion when cleaned, and must not be used.
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Mixing Dental Stone in a Bag

Store dental stone in resealable plastic bags. An 

8- by 12-inch resealable plastic bag can store two 

pounds of dental stone powder. With premeasured 

bags, casting impressions at the crime scene 

involves only adding water. The bag containing 

the dental stone powder can be used to mix and 

pour the dental stone. 

To make a cast, add the appropriate amount of 

water to the bag and close the top. Mix the casting 

material by vigorously massaging it through the 

bag for 3–5 minutes. Ensure that the material in 

the corners of the bag is also mixed. After it has 

been mixed, the material should have the 

consistency of pancake batter or heavy cream.

Mixing Dental Stone in a Bucket or Bowl

If the impressions are numerous or large, it may 

be necessary to mix larger quantities of dental 

stone in a bucket or bowl. The dental stone should 

be added slowly to the water and stirred 

continuously for 3–5 minutes. After it has been 

mixed, the material should have the consistency 

of pancake batter or heavy cream.

Pouring Dental Stone

Casting material has sufficient weight and volume 

to erode and destroy detail if it is poured directly 

on top of the impression. The casting material 
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should be poured on the ground next to the 

impression, allowing it to flow into the impression. 

The impression should be filled with casting 

material until it has overflowed.

If the mixture does not flow easily into all areas of 

the impression, use a finger or a small stick on the 

surface to cause the dental stone to flow into the 

impression. Do not put the stick or finger more 

than 1/4 inch below the surface of the casting 

material because it can damage the impression.

Before the cast hardens completely, write the 

date, collector’s initials, and other identifying 

information on it. In warm weather, the cast should 

be left undisturbed for at least 20–30 minutes. In 

cold weather, the cast should be left undisturbed 

longer. Casts have been destroyed or damaged 

when lifted too soon. If the cast is in sand or loose 

soil, it should lift easily. Casts in mud or clay may 

require careful treatment and excavation when 

being removed.

Allow the cast to air-dry for at least 48 hours. 

Package the cast in paper, not in plastic. An FBI 

Laboratory examiner must clean the cast.

Lifting Two-Dimensional Impressions

Lifting an impression allows for the transfer of a 
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two-dimensional residue or dust impression to a 

lifting film. It also allows the impression to be 

shipped to the Laboratory for photographing and 

examination.

Electrostatic Lifts

An electrostatic lifting device lifts footwear 

impressions from porous and nonporous surfaces 

without damaging the impressions. This device 

works on dry dust or residue impressions on clean 

surfaces but will not work if the impressions were 

wet or have become wet. Electrostatic lifting 

devices come with instructions for use.

Storing Electrostatic Lifting Film

Lifted impressions are damaged easily if the film 

is not stored properly. The film has a residual 

charge that attracts dust and debris and causes 

the film to cling to other surfaces. To preserve and 

store the lifting film containing an impression, tape 

one edge of the film securely in a clean, smooth, 

high-quality paper file folder or tape the edges 

securely in a shallow photographic paper box. 

Low-grade cardboard boxes such as pizza boxes 

must not be used because the residual charge 

on the film will pull dust from the box and 

contaminate the impression.

Items that contain a dry residue footwear 

impression must not be wrapped or stored in 
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plastic because a partial transfer of the impression 

to the plastic will occur.

Gelatin and Adhesive Lifts

Gelatin lifters can be used to lift impressions from 

porous and nonporous surfaces. Black gelatin 

lifters work well for lifting light-colored dry or wet 

impressions. White gelatin lifters can be used to 

lift impressions developed with fingerprint powders 

or impressions dark enough to contrast with a 

white background.

Adhesive lifters can be used only to lift 

impressions from smooth, nonporous surfaces. 

White adhesive lifters can be used to lift 

impressions developed with fingerprint powders. 

Transparent adhesive lifters can be used to lift 

impressions developed with black or fluorescent 

powders. Transparent tapes such as two-inch 

fingerprint-lifting tape also can be used to lift 

powdered impressions if the impressions are 

transferred to a white card.

Lifting Materials

Electrostatic: can be used on porous and 

nonporous surfaces. Used to lift dry dust and 

residue impressions. Nondestructive. Useful 

for searching for latent impressions.

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White adhesive: can be used on smooth, 

nonporous surfaces. Used to lift wet or dry 

impressions that have been chemically 

enhanced or developed with dark fingerprint 

powder.

Transparent adhesive: can be used on 

smooth, nonporous surfaces. Used to lift wet 

or dry impressions that have been treated with 

black or fluorescent fingerprint powder. Do not 

use on an original impression.

White gelatin: can be used on all porous and 

nonporous surfaces as long as the gelatin 

contrasts with an impression. Used to lift wet 

or dry impressions that have been chemically 

enhanced or developed with fluorescent 

fingerprint powder.

Black gelatin: can be used on all porous and 

nonporous surfaces. Used to lift wet or dry 

impressions. Offers good contact with most 

residue.

Searching Shoe Print and Tire Tread Files

A file of shoe manufacturers’ designs and a file of 

tire treads and other reference material can be 

searched to determine brand names and 

manufacturers.

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Questions concerning shoe print and tire tread 

evidence should be directed to 703-632-7288, 

703-632-7314, or 703-632-7315. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

For shoe print and tire tread comparisons, 

submit original evidence whenever possible 

(shoes, tires, photographic negatives, casts, 

lifts).

For shoe print and tire tread file searches, 

submit quality photographs of the 

impressions. If photographs are not available, 

submit casts, lifts, or the original evidence. 

Detailed sketches or photocopies are 

acceptable. Images of impression evidence 

may be submitted electronically. Call 

703-632-7288 for specifics on submitting 

evidence in this manner.

Unobtrusively write the collector’s initials, 

dates, and other relevant information on the 

evidence.

Air-dry and package evidence separately in 

Bubble Wrap; clean, smooth, high-quality 

paper or laminated folders; or paper bags, 

depending on the items being submitted for 

examination. 

Back to the top

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Soil Examinations

Soil examinations can determine whether soils 

share a common origin by comparing color, 

texture, and composition.

Questions concerning soil evidence should be 

directed to 703-632-8449. Follow the evidence 

submission directions, including Requesting 

Evidence Examinations and Packaging and 

Shipping Evidence.

Collect soil samples as soon as possible, 

because the soil at the crime scene can 

change dramatically.

Collect soil samples from the immediate crime 

scene area and from the logical access and 

escape route(s).

Collect soil samples where there are 

noticeable changes in color, texture, and 

composition.

Collect soil samples at a depth that is 

consistent with the depth from which the 

questioned soil may have originated.

If possible, collect soil samples from alibi

areas such as the yard or work area of the 

suspect(s).

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Submit a map identifying soil-sample 

locations.

Do not remove soil adhering to shoes, 

clothing, and tools. Do not process tools for 

latent prints. Air-dry the soil and the clothing, 

and package separately in paper bags.

Carefully remove soil adhering to vehicles. 

Air-dry the soil, and package separately in 

paper bags.

Ship known and questioned debris separately 

to avoid contamination. Submit known and 

questioned soil in leakproof containers such 

as film canisters or plastic pill bottles. Do not 

use paper envelopes or glass containers. 

Pack to keep lumps intact. 

Back to the top

Special-Event and Situational 

Awareness Support

Visual information specialists travel to the field 

and conduct digital site/venue surveys. These 

operations include three-dimensional laser 

scanning and documentation of physical 

structures and objects, 360-degree spherical 

video capture, and geographic information system 

(GIS) mapping.

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Questions concerning special-event and 

situational awareness support should be 

directed to 703-632-8194.

Tape Examinations

Tape composition, construction, and color can be 

compared with known sources. Comparisons can 

be made with the torn end of tape and a suspect 

roll of tape.

The Laboratory will examine duct, vinyl electrical, 

packaging, masking, and cellulose acetate (e.g., 

Scotch) tapes.

Questions concerning tape evidence should 

be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and

Packaging and Shipping Evidence.

Whenever possible, submit tape still adhered 

to the substrate. This minimizes the loss of 

trace evidence, latent fingerprints, or contact 

impressions. If it is not possible to submit the 

substrate, the tape may be manually removed 

and placed adhesive side down on a clean, 

colorless piece of plastic sheeting (e.g., 

transparency film or Kapak tubular rollstock), 

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not on cardboard, paper, or vinyl document 

protectors. Do not distort or tear the tape 

during removal.

If the tape is cut during removal, document 

and initial each cut. Use a method that 

produces a unique cutting pattern (e.g., 

pinking shears).

Back to the top

Toolmark Examinations

Toolmarks

Tools can bear unique microscopic characteristics 

because of manufacturing processes and use. 

These characteristics can be transferred to 

surfaces that had contact with the tools. Evidence 

toolmarks can be compared with recovered tools. 

In the absence of a questioned tool, toolmark 

examinations can determine the type of tool(s) 

that produced the toolmark and whether the 

toolmark is of value for comparison. Toolmark 

examinations also include lock-and-key 

examinations.

Fractures

Fracture examinations sometimes can be used to 

determine whether evidence was joined together 

and subsequently broken apart.

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Questions concerning toolmark evidence 

should be directed to 703-632-8442. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

If possible, submit the tool-marked evidence.

If it is not possible to submit the tool-marked 

evidence, make a cast to submit to the 

Laboratory.

Use an acrylic-surface replica cast kit. 

Call the Laboratory at 703-632-8442

regarding the appropriate cast kit.

Different formulas are used in different 

temperatures. If possible, move the 

evidence to a warm area.

Casts will duplicate foreign material in the 

stamped characters. Clean the area 

before proceeding. Remove paint and dirt 

with a solvent such as acetone, gasoline, 

or paint remover. Use Naval Jelly to 

remove rust. Use a soft brush. Do not use 

a wire brush.

Build a dam around the stamped 

characters to retain the acrylic liquid 

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2.

3.

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while it hardens. Use a soft and pliable 

dam material such as modeling clay. 

Ensure there are no voids in the dam.

Following the instructions in the kit, mix 

the liquid and powder for one minute and 

pour the mixture into the dam.

The acrylic liquid will take 30 minutes to 

harden. Remove the cast when it is hard. 

If paint and rust are on the cast, make 

additional casts and submit the cleanest 

one to the Laboratory.

Indicate where on the object (often a 

vehicle) the cast was taken.

Pack the cast to prevent breakage.

Photographs locate toolmarks but are of no 

value for identification purposes.

Obtain samples of any material deposited on 

the tools. Submit samples in leakproof 

containers such as film canisters or plastic pill 

bottles.

To avoid contamination, do not place the tool 

against the tool-marked evidence.

5.

6.

7.

8.

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Submit the tool rather than making test cuts or 

impressions.

Mark the ends of the evidence and specify 

which end was cut during evidence collection. 

Back to the top

Toxicology Examinations

The Toxicology discipline of the FBI Laboratory is 

accredited by the American Board of Forensic 

Toxicologists. Toxicology examinations can 

disclose the presence of drugs and poisons in 

biological specimens and food products. The 

examinations can determine the circumstances 

surrounding drug- or poison-related homicides, 

suicides, and accidents.

Because of the large number of potentially toxic 

substances, it may be necessary to screen for 

classes of poisons. Examples include:

Volatile compounds (ethanol, methanol, 

isopropanol).

Heavy metals (arsenic).

Nonvolatile organic compounds (drugs of 

abuse, pharmaceuticals).

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Miscellaneous (strychnine, cyanide).

Questions concerning toxicology evidence 

should be directed to 703-632-8441. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

Accepting evidence in alleged poison 

investigations will be based on whether the 

victim(s) sought medical attention or a 

suspicious death occurred. A doctor’s medical 

evaluation and report must be included with 

the evidence.

Biological evidence in drug-facilitated assaults 

must include a urine sample. The urine must 

be collected as soon as possible after the 

assault but must not have been collected 

more than 96 hours after the alleged 

drugging.

Toxicological analysis of hair specimens will 

be performed only for specific drugs or 

poisons. Call the Laboratory at 

703-632-8441 prior to submitting hair to 

ensure that the evidence will be accepted 

for examination. The communication 

accompanying the evidence must reference 

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the telephone conversation accepting the 

evidence.

The quantity of biological specimens 

submitted depends on whether the identity of 

a toxic substance is known, the route of 

administration, the time after exposure that 

biological specimens are collected, and 

whether subjects(s) or victim(s) are living or 

deceased. Call the Laboratory at 

703-632-8441 prior to submitting the 

specimens to ensure that the correct 

quantity is submitted. The communication 

accompanying the evidence must reference 

the telephone conversation accepting the 

evidence.

Each biological specimen must be placed in 

separate, labeled, sealed glass tubes, plastic 

cups, or heat-sealed or resealable plastic 

bags. Affix BIOHAZARD labels to the inside 

and outside containers. 

Refrigerate or freeze biological specimens 

during storage and shipping to prevent 

deterioration. Pack so that no breakage, 

leakage, or contamination occurs.

Submit a copy of the autopsy or incident 

report.

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Describe the symptoms of the suspect(s) or 

victim(s) at the time of the crime or prior to the 

death.

List any known or questioned drugs 

consumed by or prescribed for the 

suspect(s) or victim(s).

Describe any known or questioned 

environmental exposure to toxic 

substances by the suspect(s) or victim(s). 

Back to the top

Video Examinations

Video examinations are conducted by the FBI’s 

Operational Technology Division (OTD), Digital 

Evidence Laboratory (DEL), Forensic Audio, 

Video, and Image Analysis Unit (FAVIAU). The 

OTD DEL has different acceptance criteria and a 

different physical address than the FBI Laboratory, 

as described below.

Authenticity

Authenticity examinations are conducted to 

determine whether video recordings are original, 

continuous, unaltered, and consistent with the 

operation of the recording device used to make 

the recording.

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Enhancement

Enhancement examinations are conducted to 

maximize the clarity of the video signal.

Video Image Processing

Enhanced still images can be produced from 

images on video and made as prints or digital 

files.

Standards Conversion

Video can be converted from one standard to 

another (e.g., PAL to NTSC or SECAM).

Format Conversion

Video can be converted from one format to 

another (e.g., Beta to VHS).

Synchronization

Audio and video signals can be combined to 

produce one composite recording.

Special Effects

Special effects, such as a mosaic or blur spot, can 

be added to video recordings to protect a person’s 

identity.

Damaged Media Repair

Video recordings can be repaired, restored, or 

retrieved for playback and examination, if damage 

is not too extensive.
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Questions concerning video examinations 

should be directed to 703-985-1393. Questions 

concerning video evidence should be directed 

to 703-985-1388. 

Video examinations may not be submitted directly 

from entities outside the FBI. State, local, or 

international agency cases must be submitted by 

the FBI field office servicing the area and must 

meet one of the following two criteria: 1) the state, 

local, or international case has a nexus to an 

ongoing FBI investigation or 2) the FBI division 

head deems that the case is of enough regional 

importance to merit the dedication of federal 

resources to the state, local, or international case. 

These criteria shall be met with a written 

statement from the division head (Special Agent in 

Charge). FBI entities may submit cases directly.

Follow the evidence submission directions, 

including Requesting Evidence Examinations

and Packaging and Shipping Evidence.

Write-protect the original media. Never use 

the Pause operation when viewing original 

video recordings.

Submit original video recordings. If originals 

cannot be obtained, call for further 

instructions.

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Queue the original videotape to the 

approximate time of the pertinent area. State 

in a communication the date and time of the 

pertinent area, and use the date-time stamp 

on the video or the counter indicator (set from 

the beginning of the tape at 000).

Label the outer container “FRAGILE, 

SENSITIVE ELECTRONIC EQUIPMENT” or 

“FRAGILE, SENSITIVE AUDIO/VIDEO 

MEDIA” and “KEEP AWAY FROM MAGNETS 

OR MAGNETIC FIELDS.”

Address the outer container as follows: 

FORENSIC PROGRAM

BUILDING 27958A 

ENGINEERING RESEARCH FACILITY

FEDERAL BUREAU OF INVESTIGATION

QUANTICO VA 22135

Back to the top

Weapons of Mass Destruction 

Examinations

A weapon of mass destruction (WMD) is typically 

associated with nuclear and/or radiological, 

biological, or chemical agents; however, it also 

may be an explosive. WMDs are designed to 

cause a large amount of destruction or disruption 

to people and infrastructures.

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The FBI Laboratory has formalized partnerships 

with a variety of government, academic, and 

private laboratories to conduct forensic 

examinations of evidence that either contains or is 

contaminated with hazardous chemical, biological, 

and/or radiological material.

Depending on the nature of the threat—i.e., 

chemical, biological, or radiological—evidence 

examinations will be conducted by the Laboratory 

or at a designated FBI partner laboratory specially 

equipped to handle hazardous materials.

The Laboratory can direct or apply the use of 

specialized analytical techniques to identify and 

characterize a wide range of biological pathogens, 

toxins, chemical agents, toxic chemicals, and 

trace radioactive compounds that constitute a 

suspected or potential WMD.

The FBI’s Hazardous Evidence Analysis Team 

(HEAT), composed of forensic examiners and 

technicians from the various FBI Laboratory 

disciplines, is trained to safely conduct traditional 

examinations of hazardous evidence. These 

examinations are conducted at FBI partner 

laboratories.

Suspected or confirmed WMD crime scenes 

should be handled only by qualified personnel. 
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Upon notification or suspicion of a possible 

WMD incident, contact the FBI’s Strategic 

Information and Operations Center at 

202-323-3300 and ask for the Weapons of 

Mass Destruction Operations Unit Duty Officer.

Before it can be analyzed by the Laboratory or 

partner laboratories, suspected or confirmed 

WMD evidence must be properly field-screened 

by qualified personnel to determine the absence 

or presence of hazardous materials. Questions

concerning WMD evidence examinations 

should be directed to 703-632-7766.

Back to the top

Wood Examinations

Wood examinations can match sides, ends, and 

fractures; determine wood species; and compare 

wood particles found on clothing, vehicles, and

other objects with wood from the crime scene.

Questions concerning wood evidence should 

be directed to 703-632-8449. Follow the 

evidence submission directions, including 

Requesting Evidence Examinations and 

Packaging and Shipping Evidence.

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Crime Scene Safety

Personnel have the ultimate responsibility to 

recognize chemical, biological, and physical 

hazards when processing a crime scene. 

However, it is the responsibility of each agency 

responding to and providing support at the crime 

scene to develop policies, programs, and training 

on health and safety practices. 

Always consult local, state, and federal 

environmental and occupational health and safety 

laws when working with forensic evidence. All 

shipping of forensic evidence must comply with 

U.S. Department of Transportation and 

International Air Transport Association regulations. 

This section describes the hazards, safety 

precautions, safe work practices, and personal 

protective equipment recommended for personnel 

processing routine crime scenes. This section also 

explains the importance of complying with wastedisposal regulations. 

Routes of Exposure

Personnel operating in or around contaminated 

environments must be aware of the various ways 

in which hazards may enter and harm the body.1

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Inhalation

Inhalation is the introduction of a toxic product by 

the respiratory system. Airborne contaminants 

may be in the form of a dust, aerosol, smoke, 

vapor, gas, or fume. Materials may be in a solid or 

liquid form and still represent an inhalation hazard 

because they produce vapors, mists, and fumes.

Proper work practices and adequate ventilation 

can minimize the risk of airborne-contaminant 

inhalation. When working in areas with airborne 

contaminants present, personnel must wear 

respiratory protection. Personnel must be certified 

to wear respiratory protection and, therefore, to 

work in areas containing airborne contaminants.

Skin Contact

Contamination through the skin can result from 

direct contact or by absorption. The severity of the 

injury can depend on the concentration of the 

contaminant and the amount of exposure time. 

Systemic effects—such as dizziness, tremors, 

nausea, blurred vision, liver and kidney damage, 

shock, or collapse—can occur when the 

substances are absorbed through the skin and 

circulated throughout the body. Exposure can be 

prevented by using personal protective equipment 

(e.g., gloves, safety glasses, goggles, face 

shields, and protective clothing).
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Ingestion

Ingestion involves introducing contaminants into 

the body through the mouth. Ingestion can cause 

severe damage to the mouth, throat, and digestive 

tract. To prevent entry of contaminants into the 

mouth, safe work practices—such as washing 

hands before eating, smoking, or applying 

cosmetics—must always be used. Personnel 

should not bring food, drinks, or cigarettes into 

areas where contamination can occur, regardless 

of personal protection they may be wearing.

Injection

The direct injection of contaminants into the 

body—either by needle sticks or mechanical 

injuries from contaminated glass, metal, or other 

sharp objects—can cause severe complications. 

Contaminants enter directly into the bloodstream 

and can spread rapidly. Extreme caution should 

be exercised when handling objects with sharp or 

jagged edges. Work gloves must be worn at all 

times. 

Safety

Bloodborne Pathogen Safety

On December 6, 1991, OSHA issued Title 29, 

Section 1910.1030, of the Code of Federal 

Regulations (CFR), Bloodborne Pathogens.

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Handbook of Forensic Services 2007

Occupations at risk for exposure to bloodborne 

pathogens include law enforcement, emergency 

response, and forensic laboratory personnel.

Fundamental to the bloodborne pathogens 

standard is the concept of following universal 

precautions. This concept is the primary 

mechanism for infection control. It requires that 

employees treat all blood, body fluids, or other 

potentially infectious materials as if infected with 

bloodborne diseases, such as the hepatitis B virus 

(HBV), the hepatitis C virus (HCV), and the human 

immunodeficiency virus (HIV). The following 

protective measures should be taken to avoid 

direct contact with potentially infectious materials:

Use barrier protection—such as disposable 

gloves, coveralls, and shoe covers—if contact 

with potentially infectious materials may occur. 

Change gloves when torn or punctured or 

when their ability to function as a barrier is 

compromised. Wear appropriate eye and face 

protection to protect against splashes, sprays, 

and spatters of potentially infectious materials.

Wash hands after removing gloves or other 

personal protective equipment. Remove 

gloves and other personal protective 

equipment in a manner that will not result in 

contaminating unprotected skin or clothing.

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Prohibit eating, drinking, smoking, or applying 

cosmetics where human blood, body fluids, or 

other potentially infectious materials are 

present, regardless of personal protection that 

may be worn.

Place contaminated sharps in appropriate 

closable, leakproof, puncture-resistant 

containers when transported or discarded. 

Label the containers with a BIOHAZARD 

warning label.

Do not bend, re-cap, remove, or otherwise 

handle contaminated needles or other sharps.

After use, decontaminate equipment with a 

daily prepared solution of household bleach 

diluted 1:10 or with 70 percent isopropyl 

alcohol or other appropriate disinfectant. 

Noncorrosive disinfectants are commercially 

available. It is important to allow sufficient 

contact time for complete disinfection.

In addition to universal precautions, 

engineering controls and prudent work 

practices can reduce or eliminate exposure to 

potentially infectious materials. Examples of 

engineering controls include long-handled 

mirrors used to locate and retrieve evidence in 

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confined or hidden spaces and punctureresistant containers used to store and dispose 

of sharps and paint stirrers.

Chemical Safety

Depending on the type of material encountered, a 

variety of health and safety hazards can exist. 

Some of these hazards are identified by the 

following categories:1, 3

Flammable or combustible materials—such as 

gasoline, acetone, and ether—ignite easily 

when exposed to air and an ignition source, 

such as a spark or flame.

Over time, some explosive materials, such as 

nitroglycerine and nitroglycerine-based 

dynamite, deteriorate to become chemically 

unstable. In particular, ether will form 

peroxides around the mouth of the vessel in 

which it is stored. All explosive materials are 

sensitive to heat, shock, and friction.

Pyrophoric materials—such as phosphorus, 

sodium, and barium—can be liquid or solid 

and can ignite without an external ignition 

source in air temperatures less than 130 

degrees Fahrenheit (540 degrees Celsius).

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Oxidizers—such as nitrates, hydrogen 

peroxide, and concentrated sulfuric acid—are 

chemical compounds that readily yield oxygen 

to promote combustion. Avoid storage with 

flammable and combustible materials or 

substances that could rapidly accelerate their 

decomposition.

Corrosive materials can cause destruction to 

living tissue or objects such as wood and 

steel. The amount of damage depends on the 

concentration and duration of contact. 

When working with chemicals, be aware of 

hazardous properties, disposal techniques, 

personal protection, packaging and shipping 

procedures, and emergency preparedness. 

This awareness comes from appropriate 

training and the information in a Material 

Safety Data Sheet. The Material Safety Data 

Sheet provides information on the hazards of 

a particular material so that personnel can 

work safely and responsibly with hazardous 

materials.

Light-Source Safety

When using ultraviolet lights, lasers, and other 

light sources, personnel must protect their eyes 

from direct and indirect exposure.4 Not all laser 

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Handbook of Forensic Services 2007

beams are visible, and irreversible eye damage 

can result from exposure to direct or indirect light 

from reflected beams. Prolonged exposure to the 

skin also should be avoided. 

All personnel in the vicinity of the light source 

should wear protective eyewear appropriate for 

the light source. Goggles must have sufficient 

protective material and fit snugly to prevent light 

from entering at any angle. The goggles must 

display the American National Standards 

Institute’s (ANSI’s) mark denoting eye-protection 

compliance. Laser-protective eyewear must be of 

the appropriate optical density to protect against 

the maximum operating wavelength of the laser 

source.

Confined-Space Safety

A confined space is an enclosed area large 

enough for personnel to enter and work, but it has 

limited or restricted means for entry and exit. 

Confined spaces (e.g., sewers, open pits, tank 

cars, and vats) are not designed for continuous 

occupancy. Confined spaces can expose 

personnel to hazards including toxic gases, 

explosive or oxygen-deficient atmospheres, 

electrical dangers, or materials that can engulf 

personnel entering the space.5
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Conditions in a confined space must be 

considered dangerous, and personnel may not 

enter the space until a confined-space permit has 

been issued. The atmosphere must be monitored 

continuously with a calibrated, direct-reading 

instrument for oxygen, carbon monoxide, 

flammable gases and vapors, and toxic air 

contaminants. Periodic readings from these 

monitors should be documented. Only certified 

confined-space personnel may operate in 

confined spaces. Rescue services must be 

immediately available to the site.

The following practices must be followed when 

working in a confined space:

Never enter before all atmospheric, 

engulfment, mechanical, and electrical 

hazards have been identified and 

documented. Isolating hazards must be 

performed in accordance with OSHA 29 CFR 

1910.147, The Control of Hazardous Energy 

(Lockout/Tagout).6

Provide ventilation. Ensure that ventilation 

equipment does not interfere with entry, exit, 

or rescue procedures.

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Provide barriers to warn unauthorized 

personnel and to keep entrants safe from 

external hazards.

Provide constant communication between 

personnel entering the confined space and 

attendants.

Ensure that back-up communication is in 

place prior to entry.

Wear appropriate personal protective 

equipment, such as self-contained breathing 

apparatus (SCBA), a full-body harness, head 

protection, and other necessary equipment.

Never attempt a rescue unless part of a 

designated rescue team.

Ensure that personnel certified in first aid and 

CPR (cardiopulmonary resuscitation) are 

on-site. 

For additional information, refer to the OSHA 

standard for Permit-Required Confined 

Spaces, 29 CFR 1910.146.7

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Excavation Safety

All excavations must meet the requirements set 

forth in OSHA’s standards for excavations, 

29 CFR 1926.650,8 1926.651,9 and 1926.652.10

Each employee in an excavation shall be 

protected from cave-ins by an adequate protective 

system designed in accordance with 29 CFR 

1926.652(b) or 29 CFR 1926.652(c),10 unless 

excavations are less than five feet in depth and 

examination of the ground is made by a 

competent person to prevent cave-ins. A 

competent person is someone capable of 

identifying existing and predictable hazards in 

the surroundings or working conditions that are 

unsanitary, hazardous, or dangerous to 

employees and who has the authorization to take 

prompt corrective action to eliminate those 

hazards. 

As with all excavations, personnel should be 

aware of buried utilities and control standing 

water, hazardous environments, confined spaces, 

and oxygen-deficient atmospheres. 

X-Ray Safety

Portable, handheld X-ray machines, often used to 

identify the contents of unknown packages, pose 

a risk for exposure to X-ray radiation at crime 

scenes.
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Keep X-ray exposure as low as reasonably 

achievable by adhering to the following:

Shield the X-ray device, the questionable 

object, and the operator.

Remove all nonessential personnel from the 

X-ray field.

Limit the time that personnel must be in the 

area of operation.

Always wear assigned monitoring devices 

appropriate for X-ray radiation.

Ensure that standard X-ray operating 

procedures are in place and followed and that 

adequate training has been provided in 

accordance with federal and state regulations.

Back to the top

Personal Protective Equipment

At all crime scenes, the selection of personal 

protective equipment must be done in 

coordination with a hazard risk assessment 

completed by trained and qualified personnel. The 

hazard risk assessment should identify the 

possible contaminants as well as the hazards 

associated with each product. Depending on the 

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outcome of the assessment or uncertainty of the 

hazards associated with the given scene, OSHA’s 

standard for Hazardous Waste Operations and 

Emergency Response, 29 CFR 1910.120,11 may 

need to be applied. Entry into these types of 

scenes will depend on each law enforcement 

organization’s available equipment, situational 

training, and qualified personnel.

Hand Protection

Hand protection should be selected on the basis 

of the type of material being handled and the 

hazard(s) associated with the material.12, 13

Detailed information can be obtained from the 

manufacturer. The following list provides 

information about glove material types and 

functions:

Nitrile provides protection from acids, alkaline 

solutions, hydraulic fluid, photographic 

solutions, fuels, lubricants, aromatics, 

petroleum, and chlorinated solvents. It also 

offers some resistance to cuts and snags.

Neoprene offers resistance to oil, grease, 

acids, solvents, alkalies, bases, and most 

refrigerants.

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Polyvinyl chloride (PVC) is resistant to 

alkalies, oils, and limited concentrations of 

nitric and chromic acids.

Latex (natural rubber) resists mild acids, 

caustics, detergents, germicides, and ketonic 

solutions. Latex will swell and degrade if 

exposed to gasoline or kerosene. When 

exposed to prolonged, excessive heat or 

direct sunlight, latex gloves can degrade, 

causing the glove material to lose its integrity.

Using powder-free gloves with reduced 

protein content reduces the risk of developing 

latex allergies. Personnel allergic to latex 

usually can wear nitrile or neoprene.

Guidelines for glove use include the following:

Prior to donning gloves, inspect them for 

holes, punctures, and tears. Remove rings or 

other sharp objects that can cause punctures.

When working with heavily contaminated 

materials, wear a double layer of gloves.

Change gloves when they become torn or 

punctured or when their ability to function as a 

barrier is compromised.

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To avoid contaminating unprotected skin or 

clothing, remove disposable gloves by 

grasping the cuffs and pulling them off inside 

out. Discard disposable gloves in designated 

containers. Do not reuse. 

Eye Protection

Personnel handling chemical, biological, and 

radioactive materials should wear appropriate 

eye protection, such as safety glasses and 

goggles.1, 14 Face shields offer better protection 

when there is a potential for splashing or flying 

debris. Face shields must be worn in combination 

with safety glasses or goggles because face 

shields alone are not considered appropriate eye 

protection.

Contact lens users must wear safety glasses or 

goggles to protect the eyes. In the event of a 

chemical splash into the eye, it can be difficult to 

remove the contact lens to irrigate the eye, and 

contaminants can be trapped behind the contact 

lens.

Protective eyewear also should be worn over 

prescription glasses. Alternately, safety glasses 

may be made to the wearer’s eyeglass 

prescription.

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Foot Protection

Shoes that completely cover and protect the foot 

are essential.12, 15 Protective footwear should be 

worn at crime scenes when there is a danger of 

foot injuries from falling or rolling objects, from 

objects piercing the sole, or from exposure to 

electrical hazards. The standard recognized by 

OSHA for protective footwear is the American 

National Standard for Personal Protection—

Protective Footwear, ANSI Z41-1991.16 In some 

situations, nonpermeable shoe covers can provide 

barrier protection to shoes and prevent the 

transfer of contamination outside the crime scene.

Respiratory Protection

Certain crime scenes, such as bombings and 

clandestine laboratories, can produce noxious 

fumes and other airborne contaminants in which 

responders must use respiratory protection.1, 12, 17

Compliance with 29 CFR 1910.134, Respiratory 

Protection,

18 is mandatory whenever respirators 

are used. Critical elements for the safe use of 

respirators include a written program, training, 

medical evaluation, fit testing, and a respirator 

maintenance program. Without these elements, 

the wearer is not guaranteed protection.
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Head Protection

At certain crime scenes where structural damage 

has occurred or may occur, protective helmets 

should be worn. The standard recognized by 

OSHA for protective helmets is ANSI’s 

requirements for industrial head protection, 

Z89.1-2003.19

Back to the top

Hazardous Materials Transportation

All shipments of suspected or confirmed 

hazardous materials must comply with U.S. 

Department of Transportation and International Air 

Transport Association regulations. Title 49 of the 

CFR lists specific requirements that must be 

observed when preparing hazardous materials for 

shipment by air, land, or sea.20 In addition, the 

International Air Transport Association annually 

publishes Dangerous Goods Regulations,

21 which 

details how to prepare and package shipments for 

air transportation.

Title 49 CFR 172.101 provides a Hazardous 

Materials Table22 that identifies items considered 

hazardous for the purpose of transportation. 

Title 49 CFR 172.101 also addresses special 

provisions for certain materials, hazardous 

materials communications, emergency response 

information, and training requirements for 
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shippers. Personnel who serve any function in the 

shipment of hazardous materials must receive the 

specified training prior to shipping any materials 

by commercial transportation.

Back to the top

Hazardous Waste Regulations

The U.S. Environmental Protection Agency’s 

Resource Conservation and Recovery Act 

(RCRA),23 commonly referred to as the “cradle-tograve” regulation, was established to track 

chemicals from “cradle,” or generation, to “grave,” 

or disposal. This system imposes requirements on 

both generators and transporters, as well as on 

transport, storage, and disposal facilities. RCRA 

specifies that once a material is determined to be 

hazardous, it becomes the generator’s complete 

responsibility.

The process for determining whether a material is 

a hazardous waste should be completed by 

qualified personnel. Even new material in its 

original container may be considered waste if 

there is no use for it. The services of a hazardous 

waste contractor and transporter can be used to 

help remove materials from scenes. Hazardous 

materials that are removed from crime scenes are 

considered evidence and would not fall under 

RCRA waste provisions. However, when a case 
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has been adjudicated or, for other reasons, the 

material is not needed, the immediate assistance 

of a qualified contractor knowledgeable about 

local regulations must be sought. Clandestine 

drug laboratories and environmental crime scenes 

are examples of situations that may require the 

removal of waste.

Back to the top

References

1. National Research Council. Committee on 

Hazardous Substances in the Laboratory. Prudent 

Practices for Handling Hazardous Chemicals in 

Laboratories. National Academy Press, 

Washington, D.C., 1981.

2. Bloodborne Pathogens, 29 CFR 1910.1030, 

U.S. Department of Labor, Occupational Safety 

and Health Administration, Washington, D.C. 

Available: http://www.osha.gov/pls/oshaweb/

owadisp.show_document?p_table=standards

&p_id=10051.

3. Upfal, M. J. Pocket Guide to First Aid for 

Chemical Injuries. Genium, Schenectady, New 

York, 1993.
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Handbook of Forensic Services 2007

4. American National Standards Institute. 

American National Standard for Safe Use of 

Lasers (ANSI Z136.1-2000). American National 

Standards Institute, New York, 2000.

5. Conforti, J. V. Confined Space Pocket Guide. 

Genium, Schenectady, New York, 1996.

6. The Control of Hazardous Energy (Lockout/

Tagout), 29 CFR 1910.147, U.S. Department of 

Labor, Occupational Safety and Health 

Administration, Washington, D.C. Available: 

http://www.osha.gov/pls/oshaweb/owadisp.show

_document?p_table=standards&p_id=9804.

7. Permit-Required Confined Spaces, 29 CFR 

1910.146, U.S. Department of Labor, 

Occupational Safety and Health Administration, 

Washington, D.C. Available: http://www.osha.gov/

pls/oshaweb/owadisp.show_document?p_table

=standards&p_id=9797.

8. Scope, Application, and Definitions Applicable 

to This Subpart, 29 CFR 1926.650, U.S. 

Department of Labor, Occupational Safety and 

Health Administration, Washington, D.C. 

Available: http://www.osha.gov/pls/oshaweb/

owadisp.show_document?p_table=standards&p

_id=10774. 
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9. Specific Excavation Requirements, 29 CFR 

1926.651, U.S. Department of Labor, 

Occupational Safety and Health Administration, 

Washington, D.C. Available: http://www.osha.gov/

pls/oshaweb/owadisp.show_document?p_table

=standards&p_id=10775.

10. Requirements for Protective Systems, 29 CFR 

1926.652, U.S. Department of Labor, 

Occupational Safety and Health Administration, 

Washington, D.C. Available: http://www.osha.gov/

pls/oshaweb/owadisp.show_document?p_table

=standards&p_id=10776. 

11. Hazardous Waste Operations and Emergency 

Response, 29 CFR 1910.120, U.S. Department of 

Labor, Occupational Safety and Health 

Administration, Washington, D.C. Available: 

http://www.osha.gov/pls/oshaweb/owadisp.show

_document?p_table=standards&p_id=9765.

12. Office of Environmental Health and Safety. 

Laboratory Survival Manual. University of Virginia, 

Charlottesville, Virginia, 1998. Available: 

http://ehs.virginia.edu/chem/home.html.

13. Choose the proper gloves for chemical 

handling. In: Best’s Safety Directory. A. M. Best, 

Oldwick, New Jersey, 1998.
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Handbook of Forensic Services 2007

14. American National Standards Institute. 

American National Standard Practice for 

Occupational and Educational Eye and Face

Protection (ANSI Z87.1-2003). American National 

Standards Institute, New York, 2003.

15. Occupational Foot Protection, 29 CFR 

1910.136, U.S. Department of Labor, 

Occupational Safety and Health Administration, 

Washington, D.C. Available: http://www.osha.gov/

pls/oshaweb/owadisp.show_document?p_table

=standards&p_id=9786.

16. American National Standards Institute. 

American National Standard for Personal 

Protection—Protective Footwear (ANSI Z41-

1991). American National Standards Institute, 

New York, 1991.

17. Gorman, C. Hazardous Waste Handling 

Pocket Guide. Genium, Schenectady, New York, 

1997.

18. Respiratory Protection, 29 CFR 1910.134, 

U.S. Department of Labor, Occupational Safety 

and Health Administration, Washington, D.C. 

Available: http://www.osha.gov/pls/oshaweb/

owadisp.show_document?p_table=standards&p

_id=12716.
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Handbook of Forensic Services 2007

19. American National Standards Institute. 

American National Standard for Personnel 

Protection—Protective Headwear for Industrial 

Workers—Requirements (ANSI Z89.1-2003). 

American National Standards Institute, New York, 

2003.

20. Transportation, 49 CFR 100–185, U.S. 

Department of Transportation, Washington, D.C. 

Available: http://www.access.gpo.gov/nara/

cfr/waisidx_05/49cfr172_05.html.

21. International Air Transport Association. 

Dangerous Goods Regulations. 44th ed., 

Montreal, Canada, 2003.

22. Hazardous Materials Table, 49 CFR 172.101, 

U.S. Department of Transportation, Washington, 

D.C. 

Available: http://www.access.gpo.gov/nara/

cfr/waisidx_05/49cfr172_05.html.

23. Resource Conservation and Recovery Act, 40 

CFR 3001–3020, U.S. Environmental Protection 

Agency, Washington, D.C. Available: 

http://www.epa.gov/region5/defs/html/rcra.htm. 

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Crime Scene Search

Crime scenes involving suspected or 

confirmed weapons of mass destruction 

(WMD) (nuclear and/or radiological, biological, 

chemical, or explosive agents) should be 

handled only by qualified personnel. The FBI 

is the lead federal agency of a suspected or 

confirmed WMD crime scene. Specific 

information on how to process a hazardous 

materials crime scene is not covered in this 

section. Upon notification or suspicion of a 

possible WMD incident, contact the FBI’s 

Strategic Information and Operations Center at 

202-323-3300 and ask for the Weapons of Mass 

Destruction Operations Unit Duty Officer. 

A crime scene search is planned, coordinated, 

and executed by law enforcement officials to 

locate physical evidence.

Basic Principles

The best search options are usually the 

most difficult and time-consuming.

Physical evidence cannot be 

overdocumented.

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There are two search approaches:

A cautious search of visible areas, 

avoiding evidence loss or contamination.

A vigorous search of concealed areas. 

Preparation

Obtain a search warrant, if necessary.

Discuss the search with involved personnel 

before arriving at the scene, if possible.

Establish a command headquarters for 

communication and decision making in major 

or complicated crime scene searches.

Ensure that personnel are aware of the types 

of evidence usually encountered and the 

proper handling of the evidence.

Make preliminary personnel assignments 

before arriving at the scene, if possible.

Establish communication between the medical 

examiner, laboratory personnel, and 

prosecutive attorneys so that questions that 

arise during the crime scene search can be 

resolved.

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Coordinate agreements with all agencies in 

multijurisdictional crime scene searches.

Accumulate evidence collection and 

packaging materials and equipment.

Prepare the paperwork to document the 

search.

Provide protective clothing, communication, 

lighting, shelter, transportation, equipment, 

food, water, restroom facilities, medical 

assistance, and security for search personnel.

In prolonged searches, use shifts of two or 

more teams. Transfer paperwork and 

responsibility in a preplanned manner from 

one team to the next. 

Ensure that assignments are in keeping with 

the attitude, aptitude, training, and experience 

of search personnel. Personnel may be 

assigned two or more responsibilities:

Team Leader

Ensure scene security.

Prepare administrative log.

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Conduct preliminary survey (initial 

walk-through).

Prepare narrative description.

Resolve problems.

Make final decisions.

Photographer 

Photograph and log evidence and scene.

Sketch Preparer

Sketch and log scene.

Evidence Recorder

Serve as evidence custodian and log 

evidence.

Evidence Recovery Personnel

Ensure that evidence is located and 

documented (photo and sketch).

Initial and date all evidence collected.

Specialists

Brought in from the FBI Laboratory, 

private industry, academia, other 

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laboratories, etc., on a case-by-case basis 

to assist in their area of expertise.

Should be identified prior to the time they 

are actually needed.

Approach

Be alert for evidence, especially transient 

evidence.

Take extensive notes.

Consider the safety of all personnel. 

Secure and Protect

Take control of the scene immediately.

Determine the extent to which the scene has 

been protected. Obtain information from 

personnel who have knowledge of the original 

condition.

Continue to take extensive notes.

Keep out unauthorized personnel.

Record who enters and leaves. 

ü

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Preliminary Survey

The preliminary survey is an organizational stage 

to plan for the search.

Cautiously walk through the scene.

Maintain administrative and emotional control.

Select a narrative technique (written, audio, 

or video).

Take preliminary photographs.

Delineate the extent of the search area. 

Expand the initial perimeter as needed.

Organize methods and procedures. 

Recognize special problem areas.

Identify and protect transient physical 

evidence.

Determine personnel and equipment needs. 

Make specific assignments.

Determine the need for any specialists.

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Develop a general theory of the crime.

Take extensive notes to document the scene, 

physical and environmental conditions, and 

personnel movements. 

Evaluate Physical Evidence Possibilities

This evaluation begins upon arriving at the scene 

and becomes detailed in the preliminary survey 

stage.

Ensure that collection and packaging 

materials and equipment are sufficient.

Focus first on evidence that could be lost. 

Leave the least transient evidence for last.

Consider all categories of evidence 

possibilities. 

Search the easily accessible areas and 

progress to out-of-view locations. Look for 

hidden items.

Evaluate whether evidence appears to have 

been moved inadvertently.

Evaluate whether the scene appears 

contrived. 

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Narrative

The narrative is a running description of the crime 

scene.

Use a systematic approach in the narrative.

Nothing is insignificant to record if it catches 

one’s attention.

Under most circumstances, do not collect 

evidence during the narrative.

Use photographs and sketches to 

supplement, not substitute for, the narrative.

The narrative should include the following:

Case identifier.

Date, time, and location.

Weather and lighting conditions.

Identity and assignments of personnel.

Condition and position of evidence when 

an evidence recovery log is not used.

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Photography

Photograph the crime scene as soon as 

possible.

Prepare a photographic log that records all 

photographs and a description and location of 

evidence.

Establish a progression of overall, medium, 

and close-up views of the crime scene.

Photograph from eye level to represent the 

normal view.

Photograph the most fragile areas of the 

crime scene first.

Photograph all evidence in place prior to 

recovery.

All items of evidence should be photographed 

by close-ups, first without a scale and then 

with a scale, filling the frame.

Photograph the interior crime scene in an 

overlapping series using a normal lens, if 

possible. Overall photographs may be taken 

using a wide-angle lens.

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Photograph the exterior crime scene, 

establishing the location of the scene with a 

series of overall photographs including a 

landmark. Photographs should have 360 

degrees of coverage. Consider using aerial 

photography, when possible.

Photograph entrances and exits from the 

inside and the outside.

Prior to entering the scene, acquire—if 

possible—prior photographs, blueprints, or 

maps of the scene. 

Sketch

The sketch establishes a permanent record of 

items, conditions, and distance and size 

relationships.

Sketches should supplement photographs.

Sketch number designations should 

coordinate with the evidence log number 

designations.

Sketches normally are not drawn to 

scale. However, the sketch should have 

measurements and details for a 

drawn-to-scale diagram, if necessary.

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The sketch should include the following:

Case identifier.

Date, time, and location.

Weather and lighting conditions.

Identity and assignments of personnel.

Dimensions of rooms, furniture, doors, 

and windows.

Distances between objects, persons, 

bodies, entrances, and exits.

Measurements showing the location of 

evidence. Each object should be located 

by at least two measurements using an 

established measurement system, e.g., 

triangulation, transecting baseline, or 

azimuth. 

Key, legend, compass orientation, scale, 

scale disclaimer, or a combination of 

these features.

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Conduct Detailed Search

Use a search pattern (grid, strip or lane, or 

spiral).

Search for evidence from the general to the 

specific.

Be alert for all evidence.

Search entrances and exits.

Record and Collect Physical Evidence

Ensure that all items are photographed prior 

to collection.

Mark evidence locations on the sketch.

Complete an evidence log noting all items of 

evidence collected. If possible, have one 

person serve as evidence custodian.

Two people should observe the evidence in 

place, then as it is collected, initialed, and 

dated. Evidence items are marked directly 

only when positive the marks will not interfere 

with subsequent forensic examination.

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Wear latex or cotton gloves to avoid leaving 

fingerprints.

Do not excessively handle the evidence after 

recovery.

Seal all evidence packages at the crime 

scene.

Obtain known standards (e.g., fiber samples 

from a known carpet).

Constantly check paperwork, packaging, and 

other information for errors. 

Final Survey

The final survey is a review of all aspects of 

the search.

Discuss the search with all personnel.

Ensure that all documentation is correct and 

complete.

Photograph the scene showing the final 

condition.

Ensure that all evidence is accounted for 

before departing the scene.

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Ensure that all supplies and equipment are 

removed from the scene.

Ensure that no areas have been overlooked in 

the detailed search.

Reconsider the need for additional specialists.

Release

Release the crime scene after the final survey.

The scene should be released only when all 

personnel are satisfied that the scene was 

searched correctly and completely.

Only the person in charge should release the 

scene.

Ensure that the appropriate inventory has 

been provided, consistent with legal 

requirements, to the person to whom the 

scene is released.

Crime scene release documentation should 

include the time and date of release, to whom 

released, and by whom released.

Once the scene has been released, reentry 

may require a warrant.

Back to the top

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Handbook of Forensic Services 2007

Index

A

Abrasives, 14

Acrylic-surface replica cast

kit, 119–121, 136–137

Adhesives, 14–15. See also

Tapes

for lifting impressions,

 127–130

Airborne contaminants, 

 148–149

Ammunition. See also

 Bullets; Firearms

 cartridge cases or 

 shotshell casings, 64

packaging, shipping, 

 labeling, 11–12, 66–68

shot pellets, buckshot, or 

 slugs, 64

wadding, 65

Anonymous Letter File, 116

Anthropological 

examinations, 15–16

Arrest photos, 77

Arson, 17

limitations, 4

Audio, 18–20

Authenticity/manipulation

detection, 18, 74, 141

See also Image analysis

Automobiles

accidents, 5, 101–102

automobile theft, 5

glass samples from, 69–71

make and model 

identification, 75

paint samples from,

 101–102

tire tread examinations,

 121–131

B

Bank robbery, surveillance 

films, 73, 75–78

Bank Robbery Note File, 116

Bank security dyes, 21

Biohazardous materials

 bloodborne pathogen 

safety, 149–152

 packaging, shipping, and 

 labeling, 9–12, 46, 68, 

 88–89, 100, 139–141

 routes of exposure in 

 contaminated 

 environments, 147–149

Biological relatives, missing 

 persons and samples 

 from, 95–97

Biological tissue sample 

 examination. See DNA 

 examinations

INDEX
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Handbook of Forensic Services 2007

Blood

 blood examination request 

 letter, 50

on clothing submitted for 

 gunshot residue 

 examination, 68

collecting from a person, 

 45–46

collecting known samples, 

 45–46, 48–50

collection, missing persons 

 and, 95–96

dried, 48–50, 96

liquid, 48

on a person, 48

stains, 49–50

on surfaces, in snow or 

water, 48

wet bloodstained garments 

 and objects, 49–50

Bloodborne pathogen safety, 

 149–152

Body fluids. See also DNA 

examinations; specific 

fluids, e.g., Blood, Saliva

Universal precautions, 

 150–152

Bones. See Anthropological 

examinations; Tissue,

bones, and teeth. See also

Skeletal samples

Buccal (oral) swab samples, 

47, 96–97

Buckshot, 64

Building materials, 22

Bullets. See also Ammunition; 

Firearms

bullet jacket alloys, 23–24

fired, 64

packaging, shipping, and 

 labeling, 66–68

Burglary, 5

C

Cameras, image analysis

and, 74, 78. See also

Photographs/photography;

Surveillance images

Carbon paper or carbon-film 

ribbon, 115

Carjacking, 5

Cartridges, cartridge cases, 

23–24, 64, 65, 66–68

Casting, See Impressions 

and casts

Caulk, 14–15

Cellular phones, 56–58

Checkwriters, 115

Chemical safety, 152–153

Chemical unknowns, 24–26

Child Exploitation and 

 Obscenity Reference File, 

 75, 78
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Handbook of Forensic Services 2007

Child pornography 

examinations, image 

 analysis, 75–79

Clocks, 93

Clothing, fabric, and textiles 

 bank security dye on, 21

 blood on, 49

 building materials debris

 on, 22

 for comparisons, 73

 controlled substances on, 

 29–30

 explosives residue on, 

 60–61

 glass samples on, 70

 gunshot residue on, 65, 68

 hair/fibers on, 71–72

 paint on, 101–102

 pepper spray or 

 pepper foam on, 

 103

 protective. See Personal 

 protective equipment

 safe insulation on, 

 118–119

 wood particles on, 146

Coded messages. See 

Cryptanalysis

Commercial electronic 

devices, 56–58

Communication devices

 interception-of-, 57–58

Computer Analysis 

 Response Team, 27

Computers

comparison, 26

computer-animated 

 modeling, 31

content, 26

deleted data files, 26

extraction, 26

format conversion, 26

keyword searching, 27

labeling and shipping,

 28–29

limited source code, 27

passwords, 27

procedures for 

 examination, 27–29

search or field 

 examination, 27–28

transaction, 26

Confined-space safety, 

154–156

Contaminated environments

routes of exposure in, 

 147–149

Controlled substances, 29–30

Cordage, 117–118

Crime scene safety. See also

 Biohazardous materials

 about, 147

 bloodborne pathogen 

 safety, 149–152

chemical safety, 152–153
188

Handbook of Forensic Services 2007

confined-space safety, 

 154–156

 hazardous materials 

 transportation, 163–164

hazardous waste 

 regulations, 164–165

light-source safety, 

 153–154

personal protective 

 equipment, 158–163

routes of exposure in 

 contaminated 

 environments, 147–149

X-ray safety, 157–158

Crime scene search 

 procedures

 approach, 175

 basic principles, 

 171–172

 final survey, 183–184

 latent prints, 80–89

 narrative, 178

 photography, 82–84, 

 86–87, 121–124, 

 179–180

 physical evidence

 possibilities evaluation, 

 177

 preliminary survey, 

 176–177

 preparation, 172–175

 record and collect, 

 182–183

 release, 184

 search, 182

 search personnel, 

 173–175

 secure and protect, 175

 sketches, 180–181

 weapons of mass 

 destruction and, 171

Crime scene surveys, 

 documentation, and 

 reconstruction, 31

Criminal Justice Information 

 Services Division, 89

Cryptanalysis, 31–33

D

Damaged media restoration

audio recordings, 19–20

video, 142–144

Debris

arson and, 17

building materials, 22

glass samples, 69–70

paint, 100–102

safe insulation and, 

 118–119

soil examinations and, 

 131–133

Decontamination/disinfection 

of equipment, 151

Demonstrative evidence, 33

Dental stone, mixing and 

pouring, 125–127
189

Handbook of Forensic Services 2007

Digital cameras and film. See

 Cameras; Film

DNA examinations

 about, 33–35

 anthropological 

 examinations of bone, 

 15–16

 buccal (oral) swabs, 47, 

 96–97

 case acceptance policy,

 35–40

 documenting, collecting, 

 packaging, and 

 preserving, 44–45

 hair, 42–44, 53–54,

 71–72

 mitochondrial DNA, 

 34–35, 40–43

 nuclear DNA, 34–35

 preserving DNA evidence, 

 55–56

 saliva, 52–53

 semen and semen stain 

 examinations, 50–52

 seminal evidence from 

 sexual assault victims, 

 52

 sources for analysis, 

 33–35

 tissue, bones, teeth, 

 54–55, 97–100

 urine, 52–53

Document age, 115

Drug records, 32

Drug residue, 30

Dyes, bank security, 21

E

Electronic devices, 56–58

Electrostatic lifts, 127–128

Elimination prints, 85

Embossings, 115

Enhancement examinations

audio recordings, 18–20

video, 142–144

Evidence

packaging and shipping, 

 9–12

submission, 7–12

Evidence examinations, 

requesting, 7–9. See also

specific items, e.g.,

Abrasives, DNA, 

Explosives

Expert witness testimony, 2–3

Explosive incidents and 

hoaxes, 4

Explosives, 58–60. See also

Chemical safety

Explosives residue, 60–61

Eye protection, 154, 161

F

Fabric and textiles, See 

Clothing, fabric, and 

textiles
190

Handbook of Forensic Services 2007

Facsimile machines, See

Electronic devices; 

Questioned document 

examinations

Facsimiles, 57, 87, 112–113

FBI Disaster Squad, 61–62

FBI Laboratory, 1–3

FBI Laboratory Evidence 

Control Unit, 7, 12

FBI Operational Technology 

Division, 1–3, 18, 27, 57, 

 72, 141

Feathers, 62–63

Fibers, 71–72

Film, image analysis, 72–79

Fingerprinting human 

 remains, 88–89. See also

 Latent prints

Fingerprints. See Latent 

 prints

Fire. See Arson

Firearms, 63–68. See also

 Ammunition; Bullets

 cartridge cases or

 shotshell casings, 64

 gun parts, 65

 gunshot residue on

 victim’s clothing, 65, 68

 image analysis, 73, 78

 shot pellets, buckshot, or 

 slugs, 64

 silencers, 66

 unfired cartridges or 

 shotshells, 65

 wadding, 65

Foot protection, 162

Footprints. See Shoe prints

Forensic facial imaging/ 

 reproduction, 16, 68–69

Forensic services

 about, 1–3

 limitations, 3–5

G

Gambling, 32

Gelatin lifts, 128–130

General unknowns (powders, 

 liquids, stains), 24–26

Glass, 69–71

Global positioning systems 

(GPSs), 56–58

Graphic arts (printing), 114

Guns. See Firearms

Gunshot residue

on clothing, 65, 68

H

Hair, 43–44, 53–54, 71–72

toxicology screening, 139

Hand protection, 159–161

Handwriting and hand 

printing, 79–80, 107–110

Hazard risk assessment, 

personal protective 

 equipment and, 158–159
191

Handbook of Forensic Services 2007

Hazardous materials handling

and transportation, 10–12, 

 163–164. See also

Biohazardous materials;

Chemical safety; specific 

hazardous materials, e.g.,

Ammunition, Explosives

Hazardous waste regulations, 

164–165

Head protection, 163

Hepatitis B and C viruses, 

150

Hit-and-run (automobile) 

 cases, 5, 101–102, 

 105–106

Human immunodeficiency 

virus (HIV),150

Human remains

anthropological 

 examinations, 15–16

hands/fingers for latent 

 prints, 88–89

samples from unidentified, 

 44, 97–100

I

Ignitable materials. See

 Arson

Image analysis

 authenticity and image-

 manipulation detection, 

 74

automobile make and 

 model identification, 75

cameras, 74

child pornography 

 examinations, 75, 78

clothing, 73, 78

film, 73–74, 76–79

firearms, 78

location, time, and date of 

 photographic evidence, 

 74

packaging, shipping, and 

 labeling of, 76–79

photogrammetry, 73, 78

photographic 

 comparisons, 73

photographs, 73–78

procedures for 

 submission, 76–79

providing originals, 76

source and age, 74

video, 73–78

Impressions and casts

 of serial/identification 

 numbers, 119–121

 three-dimensional 

 impression casts, 

 125–127

 for toolmark examinations, 

 136–137

 two-dimensional 

 impressions, 127–130

Infectious materials, 149–152
192

Handbook of Forensic Services 2007

Ingestion of contaminants, 

 149

Inhalation exposure, 148

Injection of contaminants, 

 149

Ink, 79–80

Innocent Images, 75

Insect samples, 

 anthropological 

 examinations of bone 

 and, 16

Interception-of- 

 communication (IOC) 

 devices, 57–58

L

Labels and labeling, shipping, 

9–12. See also specific 

items

Lamp bulbs, 93

Latent labels, 10

Latent prints,

 case acceptance policy, 80

 developing at crime 

 scenes, 80–82

 digital images of, 86–87

 glass samples and, 71

 lifting, 81

 packaging, shipping, and 

 labeling, 84–86

 photographing, 82–84

 submitting hands/fingers 

 of deceased for, 88–89

Lifting materials, 81, 127–130

Light-source safety, 153–154

Loan-sharking, 32

Lubricants, 89–90

M

Malicious mischief, 5

Metallurgy

broken or mechanically 

 damaged metal, 91

burned, heated, or melted 

 metal, 92

comparative examinations, 

 90–91

cut or severed metal, 92

lamp bulbs, 93

metal fragments, 92

objects with questioned

 internal components, 93

specification fraud and 

 noncompliant 

 materials, 92–93

watches, clocks, and 

 timers, 93

Minor theft and fraud, 5

Missing persons

 about samples, 94–97

 blood collection and, 

 96

 bone submissions, 97–98

 buccal (oral) swabs, 96–97

 dried bloodstains, 96
193

Handbook of Forensic Services 2007

 samples from biological 

 relatives, 95–96

 skeletal samples, 97–98

 teeth and, 98–99

 tissue samples, 100

Mitochondrial DNA (mtDNA)

 See DNA examinations

Money laundering, 32

N

National Automotive Image 

File, 75

National Center for Missing

 and Exploited Children, 75

National Integrated Ballistic 

Information Network 

(NIBIN), 64

National Missing Person 

DNA Database, 37, 40, 94

Nonfatal traffic accidents, 5

Nuclear DNA (nDNA). See

DNA examinations

O

Oleoresin capsicum. See

 Pepper spray or foam

Oral swab samples, 47, 

96–97

P

Packaging and shipping

evidence, 9–12

Pagers, 56–58

Paint, 100–102

Paper, 114–117

Pepper spray or foam, 

 103–104

Personal digital assistants, 

 (PDAs), 56–58

Personal protective 

 equipment (PPE),

 eye protection, 154, 161

 foot protection, 162

 hand protection, 159–161

 hazard risk assessment

 and, 158–159

 head protection, 163

 respiratory protection, 162

Pharmaceuticals, 104. See

also Toxicology

Photocopies, 87, 112–114, 

117, 131

Photogrammetry, 73, 78

Photographs/photography

crime scene search 

 procedures, 179–180

examination-quality, 

 122–124

image analysis, 73–75, 77

impressions in snow, 124

latent prints, 82–84

location, time, and date

 determinations and, 74

photographic 

 comparisons, 73
194

Handbook of Forensic Services 2007

shoe prints and tire 

 treads, 121–124

of suspects, 77

toolmarks, 137

Plastic bags, 115

Poisons. See Crime scene 

 safety; Toxicology

Polymers, 104–106

Pornography examinations,

 image analysis, 75–79

Printing and printed matter, 

 114

Product tampering, 106–107

Property crime, 3–5

Prostitution, 32–33

Protective clothing and

 equipment, 158–163

Q

Questioned documents,

altered or obliterated 

 writing, 110

Anonymous Letter File, 

 116

Bank Robbery Note File, 

 116

burned or charred paper, 

 114

carbon paper and 

carbon-film ribbon, 115

checkwriters, 115

document age, 115

embossings and seals, 

 115

facsimiles, 112–114

graphic arts (printing), 114

handwriting and hand 

 printing, 107–110

ink and, 79

nongenuine signatures, 

 110

packaging, shipping, and 

 labeling, 116–117

paper, 114

photocopies, 112–114, 117

plastic bags, 115

rubber stamps, 115

typewriting, 110–112

R

Racketeering records, 31–33

Respiratory protection, 148, 

 162

Rope, 117–118

Routes of exposure in 

contaminated 

environments, 147–149

Rubber stamps, 115

S

Safe insulation, 118–119

Safety. See Crime scene 

safety 

Saliva, 34, 52–53, 55–56

Sealants, 14–15
195

Handbook of Forensic Services 2007

Seals, 115

Search patterns, 182

Semen and semen stain

examinations, 50–52

Seminal evidence from

sexual assault victims, 52

Serial numbers, 119–121

Serology. See DNA 

 examinations 

Sexual assault, seminal 

evidence from, 52

Shipping of evidence. See

 Packaging and shipping 

 evidence; specific items

Shoe prints, 121–131

Shot pellets, 64

Shotshells and shotshell 

 casings, 64, 65

Signal analysis, audio 

 recordings, 19

Signatures, 110

Silencers, 66

Skeletal remains, See Human 

remains

Skeletal samples, 97–98

Skin contamination/contact, 

 148

Slugs, 64

Snow

blood in, 48

impressions in, 124

Soil, 131–133

Special-event and situational 

awareness support, 133

Submitting evidence, 7–12

Substances, unknown

(powders, liquids, stains),

 24–26

Surveillance images, 73–79

Suspects, arrest or known 

photographs of, 77

T

Tape, 134–135

 for lifting impressions, 

 128–130

 for lifting latent prints, 81

Ten-print fingerprint cards, 89

Teeth. See Tissue, bones, 

and teeth

Timers, 93

Tire treads, 121–131

Tissue, bones, and teeth

 anthropological 

examinations of 

 bone, 15–16

 DNA examinations, 54–55

 97–100

 unidentified human 

 remains, 44, 97–100

Toolmarks, 135–138

Toxicology, 138–141

Traffic accidents, 5

Typewriting, 110–112
196

Handbook of Forensic Services 2007

U

Universal precautions, 

 150–152

Urine, 52–53, 139

V

Vandalism, 5

Video, 141–144

 image analysis, 72–79

Violent crime, 3–4

Visual information 

 specialists, 31, 33, 68, 133

Voice comparisons, 18–19

W

Wadding, ammunition, 65

Watches, 93

Watermark identification, 79, 

115

Weapons of mass 

 destruction, 144–146

crime scene search

 procedures and, 171

Wood, 146

Writing examinations. See

 Handwriting and hand 

 printing; Questioned 

 documents

X

X-ray safety, 157–158

X-rays, known individual 

 comparison to skeletal 

 remains, 16
197

The Handbook of Forensic Services is also 

available online at http://www.fbi.gov/

hq/lab/handbook/forensics.pdf. Law 

enforcement officers and forensic laboratory 

personnel may obtain the handbook in 

field-manual format by faxing a request on 

agency letterhead to the FBI Laboratory 

Library at 703-632-8374.
198