OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

1

OSAC 2021-N-0019

Standard Practice for the 

Documentation and 

Processing of Shooting 

Scenes

Crime Scene Investigation & Reconstruction Subcommittee

Scene Investigation Scientific Area Committee

Organization of Scientific Area Committees (OSAC) for Forensic Science
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

2

OSAC Proposed Standard

OSAC 2021-N-0019

Standard Practice for the 

Documentation and Processing of 

Shooting Scenes

Prepared by 

Crime Scene Investigation & Reconstruction Subcommittee

Version: 2.0

November 2022

Disclaimer:

This OSAC Proposed Standard was written by the Organization of Scientific Area Committees 

(OSAC) for Forensic Science following a process that includes an open comment period. This 

Proposed Standard will be submitted to a standards developing organization and is subject to 

change. 

There may be references in an OSAC Proposed Standard to other publications under 

development by OSAC. The information in the Proposed Standard, and underlying concepts and 

methodologies, may be used by the forensic-science community before the completion of such 

companion publications.

Any identification of commercial equipment, instruments, or materials in the Proposed Standard 

is not a recommendation or endorsement by the U.S. Government and does not imply that the 

equipment, instruments, or materials are necessarily the best available for the purpose.
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

Foreword

This standard is meant for scene investigators who are responsible for the documentation of a 

shooting scene and for shooting reconstructionists performing the on-scene documentation. It 

is recognized that some shooting scenes are processed and documented by scene investigators 

who will not be performing the final reconstructive analysis. However, their work is critical to 

any subsequent reconstructive efforts. This standard provides guidance for shooting scene 

preservation and minimum documentation requirements for projectile impacts and 

trajectories. This standard cannot replace knowledge, skills, or abilities acquired through 

appropriate education, training, empirical testing, and experience and should be used in 

conjunction with sound professional judgment.

All hyperlinks and web addresses shown in this document are current as the publication date 

of this standard.

Keywords: Crime scene investigation, crime scene reconstruction, shooting reconstruction, 

projectile impact, trajectory analysis
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

Table of Contents

1 Scope 5

2 Normative References 5

3 Terms and Definitions 5

4 Procedure 8

4.1 Shooting Scene Preservation 9

4.2 Projectile Impact Documentation 9

4.3 Trajectory Measurement 10

4.4 Projectile Recovery 11

5 Examples of Additional Relevant Evidence Types and Examinations 11

6 Recording and Reporting Observations 12

7 Commonly Used Equipment 13

Annex A (informative) Bibliography 14
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

Standard Practice for Documentation and 

Processing of Shooting Scenes

1 Scope

This document provides minimum standards and recommendations for the documentation 

and processing of shooting scenes that may be subject to shooting reconstruction. This 

document covers generally accepted professional principles and operations, shooting scene 

documentation, and shooting scene preservation. This document does not provide 

complete protocols for conducting a full shooting reconstruction.

2 Normative References

ASTM E620-18. Standard Practice for Reporting Opinions of Scientific or Technical 

Experts. 

OSAC proposed standard: "Guiding Principles for Scene Investigation and 

Reconstruction"

ANSI-ASB Best Practice Recommendation 068, Safe Handling of Firearms and 

Ammunition, 1st Edition 2020.

3 Terms and Definitions

For purposes of this document, the following definitions and acronyms apply.

3.1

ammunition

Unfired cartridges designed to be discharged in a firearm.

3.2

ballistics

The science and study of projectiles in motion, which is usually divided into three 

parts: interior ballistics, exterior ballistics, and terminal ballistics.

3.3

bullet

A projectile designed specifically to be fired from a firearm.

3.4

caliber

The nominal diameter of a projectile or the nominal inner diameter of a barrel, or a 

term also used to designate the specific cartridge(s) for which a firearm is chambered.

3.5

cartridge case / casing
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

The fired or unfired component of metallic ammunition, the purpose of which is to 

hold the primer, propellant, and projectile. 

3.6

cartridge case ejection patterning

The use of the spatial relationship between a firearm and ejected cartridge 

cases/cartridges in order to approximate gun location in a scene at the time of 

ejection.

3.7

defect

A generic term for any surface damage.

3.8

directionality

The property of a trajectory that describes which way a projectile was traveling.

3.9

distance determination

The process of determining how far away the muzzle of a firearm was from a target at 

the time a shot was fired, based on one or more methods such as gunshot residue, 

petal slap, pellet patterning, or buffer patterning. 

3.10

exterior ballistics

The branch of ballistics that deals with a projectile's flight in air. Also known as 

external ballistics.

3.11

firearm

Any weapon designed to expel a projectile with the energy generated by combustion.

3.12

gunshot residue

GSR

The total of all residues resulting from the discharge of a firearm, typically constituted 

of nitrites and lead, as well as unburned and partially burned gunpowder particles, 

primer residues, carbonaceous material plus metallic residues from projectiles, 

fouling, and any lubricant associated with the projectiles. 

3.13

horizontal angle

The angle in a horizontal plane typically between the path of a bullet and an object 

that was struck, also known as azimuth angle.
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

3.14

interior ballistics

The study of a projectile's initial acceleration and performance in the weapon and the 

related processes. Also known as internal ballistics.

3.15

non-penetrating impact

Projectile damage where the projectile strikes but does not penetrate a target.

3.16

pellet patterning

The distribution of shot fired from a firearm that may be used to estimate the muzzleto-target distance. 

3.17

penetrating impact

Projectile damage where the projectile entered and did not exit a target.

3.18

perforating impact

Projectile damage where the projectile entered and exited a target.

3.19

primer residue

A subcategory of gunshot residue considering only chemicals generated from the 

priming mixture. Typically composed of very small particles containing lead, barium, 

and antimony, and detected using scanning electron microscopy. 

3.20

projectile

An object propelled with an initial velocity then acted upon by gravity, air drag, and 

other outside forces.

3.21

projectile fragment

Any portion of a projectile that retains characteristics permitting it to be identified as 

having been part of a projectile.

3.22

projectile impact, noun

Surface damage determined to have been caused by a projectile. 

3.23

range

The distance from a firearm to the initial projectile impact.
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

3.24

scene reconstruction

The utilization of information gathered from the investigative process to develop or eliminate 

possible explanations for how an incident occurred.

3.25

shooting reconstruction

A scene reconstruction focused on the discharge of a firearm(s).

3.26

target, noun

Any object struck by a projectile, regardless of whether it was struck intentionally.

3.27

terminal ballistics

The branch of ballistics that deals with the projectile's impact with a target.

3.28

trajectory

The arched path that a projectile follows in flight, typically modeled as a straight line 

for short-range paths.

3.29

trajectory analysis

The determination of a projectile's flight path.

3.30

vertical angle

The angle in a vertical plane typically between the path of a bullet and level, also 

known as elevation angle.

3.31

wound ballistics

A subset of terminal ballistics that considers projectile impacts to tissue and tissue 

simulants.

4 Procedures

This standard establishes the minimum requirements to document a shooting scene 

for reconstruction. As established in the Guiding Principles for Scene Investigation and 

Reconstruction, the specific circumstances at a scene may require deviation from 

established standards. Deviations from this standard shall be based on specific 

articulable circumstances and shall be documented. 
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

4.1 Shooting Scene Preservation

This section applies specifically to shooting incidents and should be blended with 

other scene processing procedures, as necessary. 

4.1.1 The location of firearm evidence in a scene can have critical implications to a 

shooting reconstruction, for example: impact sites, fired cartridge cases, firearms, 

and/or other ammunition components. Proper location documentation of these 

specific type(s) of evidence shall be conducted. 

a) Each fired cartridge case shall be individually labeled, headstamps described or 

photographed, and its location documented. If cartridge cases of the same type 

are commingled, they may be documented and collected together. 

b) Firearm conditions shall be documented to include safety position, cylinder 

position for revolvers, loaded status, damage, evidence of malfunction, and 

trace evidence.

c) Firearm information shall be documented to include the make, model, caliber, 

and serial number, if present.

4.1.2 Alterations to the scene that occur after an incident (e.g., first responder 

involvement, animal activity, weather, time) can greatly affect shooting scene 

reconstruction, and any known or suspected alterations shall be documented.

4.1.3 In the course of shooting scene processing, it may be necessary for the 

investigator to move objects within the scene in the interest of the investigation (e.g., 

search, body movement). This is permissible, but actions shall be taken first to record 

the object's location to allow the object to be properly replaced for analysis, if 

necessary.

4.2 Projectile Impact Documentation

All projectile impacts shall be documented to include photography, labeling, projectile 

impact characteristics, and 3-dimensional location.

4.2.1 Photography

Projectile impacts shall be photographically documented to record their location, 

scene context, and physical characteristics. 

a) In addition to standard scene photography, photography of projectile impacts 

shall include sufficient overall and mid-range images to establish the 

relationship of projectile impacts with each other and other objects in the scene 

and close-up images taken with the sensor plane parallel to the impact. 

b) Photographs shall be taken with and without a scale/label.

4.2.2 Labeling
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

Projectile impacts shall be given a unique identifier and that shall be recorded in 

photographs, notes, and sketches/diagrams. 

4.2.3 Projectile Impact Characteristics

Projectile impacts shall be examined and their characteristics documented. These 

should include, but are not limited to:

a) Physical Characteristics

i) size (width, length) 

ii) as non-penetrating, penetrating, or perforating

iii) target material

iv) specific features or characteristics of the impact that are used to further 

evaluate the projectile impact (e.g., depth)

v) any other observable forensic evidence present (e.g., trace evidence)

b) Chemical Characteristics 

i) if a projectile impact is suspect, the use of chemical testing techniques for 

traces of bullet metals should be employed

ii) copper and lead tests (e.g., dithiooxamide (DTO) & sodium rhodizonate 

tests, respectively) are commonly used field tests

4.2.4 3-Dimensional Location

The 3-dimensional location of each projectile impact shall be measured using a 

coordinate system that is clearly defined and recorded in the notes or data collected.

4.3 Trajectory Measurement

In order to measure a trajectory, the following parameters, when practicable, shall 

include:

4.3.1 Directionality

A trajectory is often represented by a line traveling in only one direction. When 

possible, the direction of travel shall be documented.

4.3.2 Impact Site(s)

a) each trajectory shall be associated with at least one reliable projectile impact

b) if more than one projectile impact is associated with a single, defined trajectory 

(e.g., primary, secondary, etc.), all the projectile impacts that can be tracked 

along that trajectory and their sequence shall be documented

4.3.3 Path
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

The projectile's path can be described with either of the following:

a) Horizontal Angle and Vertical Angle

i) angles are commonly reported to a degree (not tenths or hundredths of a 

degree)

ii) for both horizontal and vertical measurements, zero (0) must be defined 

and documented

iii) the horizontal angle is typically measured in the horizontal plane 

established relative to the object that was struck

iv) the vertical angle is typically measured from level relative to gravity

b) Three-Dimensional Representations

i) photographs of visual representations of the trajectories from which 

horizontal and vertical angles can be measured

ii) three-dimensional survey data of the trajectories

iii) horizontal and vertical angles can be calculated if appropriate threedimensional locations along a trajectory are documented

4.4 Projectile Recovery

After all other on-scene documentation and analysis are complete, every reasonable 

effort shall be made to locate and recover projectiles or projectile fragments from 

impacted objects.

a) All reasonable efforts shall be made to minimize damage to projectiles or 

projectile fragments during this process.

b) When a projectile or projectile fragment can be associated with a projectile 

impact and/or trajectory, this shall be documented in the notes.

c) The section of a target containing an embedded projectile may be collected for 

a more comprehensive attempt for recovery in a controlled environment.

d) If a projectile cannot be found or physically recovered, the reasons shall be 

documented. 

e) An accounting of the relative numbers of projectile impacts, projectiles, and 

cartridge cases shall be completed when feasible.

5 Examples of Additional Relevant Evidence Types and Examinations

5.1 Scene investigators shall be aware of other types of forensic evidence that can 

yield reconstructive value to later shooting reconstructions. Appropriate 

development, documentation, and collection techniques shall be applied for all 

evidence discovered at shooting scenes.

5.2 Additional relevant evidence types can include, but are not limited to:
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

a) Firearms Identification. The identification of ammunition components as 

having been fired from a particular firearm can allow that firearm to be 

associated with a specific trajectory and/or location in the scene.

b) Gunshot Residue (GSR) Distance Determination. GSR patterns can be used to 

determine a muzzle-to-target range at the time a shot was fired, which can 

further help to place a firearm in the scene.

c) Pellet Patterning. Pellet patterns can be used to determine a muzzle-to-target 

range at the time a shot was fired, which can further help to place a firearm in 

the scene.

d) Primer Residue Analysis. Primer residues deposited on objects near a 

discharged firearm, most notably the shooter, can be used to associate an 

individual as having been in the vicinity of a firearm discharge.

e) Cartridge Case Ejection Patterns. A cartridge case pattern analysis can be used 

to position a firearm within a scene.

f) Exterior Ballistics. Analysis of the long-range reconstruction of a bullet's path 

through the atmosphere.

g) Terminal and Wound Ballistics. Analysis which can include bullet deformation, 

penetration depth, and wound profiles.

h) Trace Evidence. Trace evidence can indicate the type of projectile or the 

presence of an intervening target. Intervening targets can have a destabilizing 

effect on the bullet's trajectory and shall be considered when drawing 

conclusions from an evaluation of the ballistic evidence.

i) Bloodstain Pattern Analysis. A bloodstain pattern analysis is a type of scene 

reconstruction that can be helpful in locating individuals in the scene and 

associating them with movements or firearms events.

j) Audio and Video Recordings. Audio and video recordings of a shooting can be 

used to establish specific timelines, relative chronologies, and the positions and 

movements of individuals in the scene.

k) Fingerprint Examination. Latent prints processing can reveal an association to 

individuals who have handled some part of the evidence or scene in a shooting 

reconstruction.

l) DNA Analysis. DNA analysis can reveal an association to individuals who have 

handled some part of the evidence or scene in a shooting reconstruction.

6 Recording and Reporting Observations

6.1 Notes shall be taken contemporaneously with the examination, which records 

pertinent observations and measurements. Notes shall:

a) provide the basis for conclusions and opinions

b) be in a common format (e.g., written, typed, diagrammed, photographed, 

scanned, audio recorded, video recorded)

c) be retained such that a peer or reviewer can thoroughly understand what was 

done 

d) contain relevant observations regarding factors that may affect uncertainty or 

confidence in a measurement or conclusion 
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

6.2 When a report is prepared, guidance on report preparation may be found in 

ASTM Practice E620-18.

7 Commonly Used Equipment

a) cameras/imaging equipment 

b) trajectory rods/probes, centering cones

c) lasers

d) strings

e) zero-edge or standard protractors

f) inclinometers

g) plumb bobs

h) 3D scanners

i) total stations

j) laser measurement tools

k) micrometers

l) calculators

m) levels

n) tripods

o) compass

p) tape measures/scales

q) chemical reagents 

r) carpenter's square
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

Appendix A

(informative) 

Bibliography

This is not meant to be an all-inclusive list, as the group recognizes other publications on this 

subject may exist. At the time this document was drafted, these were some of the publications 

available for reference. Additionally, any mention of a particular software tool or vendor as 

part of this bibliography is purely incidental, and any inclusion does not imply endorsement 

by the authors of this document.

1] Baxter, Jr., Everett. "Shooting Scene Documentation." Complete Crime Scene Investigation 

Handbook, Taylor & Francis, 2015, pp. 319-358.

2] DeFrance, Charles S. and Carlo J. Rosati. "A Practical Guide to Shooting Scene Preservation 

for Crime Scene Investigators." Journal of the Association for Crime Scene Reconstruction, vol. 

13, no. 3, 2009, pp. 29-39.

3] DiMaio, Vincent J.M. Gunshot Wounds: Practical Aspects of Firearms, Ballistics, and Forensic 

Techniques. 2nd Edition. CRC Press, 1999.

4] Gardner, Ross. "Shooting Scene Documentation and Reconstruction." Practical Crime Scene 

Processing and Investigation, 2nd Edition. CRC Press 2012, pp. 299-330. 

5] Garrison, Dean H. Jr. Practical Shooting Scene Investigation: The Investigation and 

Reconstruction of Crime Scenes Involving Gunfire. Universal Publishers, 2003.

6] Haag, Michael and Lucien Haag. Shooting Incident Reconstruction. 2nd Edition. CRC Press, 

2011.

7] Haag, Lucien C. “The Construction of an Inexpensive Portable Laser for Use in Shooting 

Reconstructions.” Association of Firearms and Tool Mark Examiners Journal, vol. 1, no. 19, 1987, pp. 

175–177.

8] Haag, Michael. “The Accuracy and Precision of Trajectory Measurements.” Association of Firearms 

and Tool Mark Examiners Journal, vol. 40, no. 2, 2008, pp. 145–182.

9] Hueske, Edward E. Practical Analysis and Reconstruction of Shooting Incidents. CRC Press, 2006

10] Noedell, Matthew. "Shooting Scene Processing and Reconstruction." Practical Crime Scene 

Analysis and Reconstruction, edited by Ross Gardner and Tom Beval, CRC Press, 2009, pp. 44-

49

11] Petraco, Nicholas and Peter DeForest. "Trajectory Reconstruction I- Trace Evidence in Flight." 

Journal of Forensic Sciences, vol. 35, no. 6, 1990, pp. 1284-1296.
OSAC 2021-N-0019 Standard Practice for the 

Documentation and Processing of Shooting Scenes

12] Priest, Jon. “Photographic Documentation of Shooting Incidents” Crime Scene Photography, 

edited by Edward Robinson, Elsevier, 2016, pp. 518-529.

13] Roberts, James. Reconstruction of a Shooting to Disprove/Prove Trajectory. Association of 

Firearms and Tool Mark Examiners Journal, 1985.

14] Rose, David. “Establishing a Maximum Effective Range for String Shooting Reconstructions.” 

Journal of Forensic Identification, vol. 55, no. 5, 2005, pp. 611-617.

15] Scientific Working Group for Firearms and Toolmarks (SWGGUN). Guidelines for Gunshot 

Residue Distance Determinations: processing, determination, distance tests. SWGGUN, 2013.

16] Scientific Working Group for Firearms and Toolmarks (SWGGUN). Projectile Path 

Reconstruction -- Essential Elements. SWGGUN, 2012.

17] Trahin, Jimmy L. “Bullet Trajectory Analysis.” Association of Firearms and Tool Mark Examiners 

Journal, vol. 19, no. 2, 1987, p. 124.