Document #20 Standard for Simultaneous Impression 

Examination (Latent), Ver. 2.0

Date of First Issue 12/05/08 Current Issue Date 12/05/08

Web Posting Date 12/24/12

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Document #20

Standard for Simultaneous Impression Examination

(Latent)

1. Preamble

1.1. This standard addresses latent print examinations when two or more friction ridge impressions are 

considered to be deposited on an object as a single act of touch, also referred to as a simultaneous 

impression.

1.2. The SWGFAST Glossary defines a simultaneous impression as “Two or more friction ridge 

impressions from the same hand or foot deposited concurrently.” Two or more latent friction ridge 

impressions from the same hand that are consistent with simultaneity can be used in the aggregate 

and considered a single impression when conducting examinations [1, 2]. The use of the term 

simultaneous impressions, with an “s”, infers that more than one simultaneous impression exists in 

a case.

1.3. This document sets forth the standard for (1) analyzing two or more friction ridge impressions to 

determine whether they are consistent with having been deposited on an object simultaneously, (2) 

analyzing a simultaneous impression to determine how it will be compared, (3) conclusions from 

the comparison of a simultaneous impression with known exemplars, (4) verification of conclusions, 

(5) documenting the examination, and (6) reporting results.

1.4. Independent of the value for individualization or exclusion, a simultaneous impression may support 

the ability to infer the handling or circumstance of touch by the fingers, hand, or foot of an object. 

Specific circumstances within a case may permit an examiner to offer an opinion as to how the 

simultaneous impression relates to the touch or grasp of an object, which subsequently may 

support or refute the circumstances of touch.

1.5. There is added discriminative value in using impressions that display evidence of simultaneity. For 

example, the aggregate comparative value of fingerprints in corresponding positions has been 

shown to be highly reliable for effecting identifications in the Automated Fingerprint Identification 

System (AFIS) environment [3].

1.6. Simultaneous impression examination is a complex application of Analysis, Comparison, 

Evaluation, and Verification (ACE-V). Before conducting a forensic examination of a simultaneous 

impression, examiners shall have completed specialized training in the examination of latent print 

simultaneous impressions. This training should include successfully completing formal instruction, 

literature reading and testing to demonstrate competency. This training and testing may be 

conducted internally or externally.
Document #20 Standard Simultaneous Impression 

Examinations, Ver. 2.0

Date of First Issue 12/05/08 Current Issue Date 11/17/12

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1.7. If a conclusion of individualization (identification), inconclusive or exclusion can be derived without 

invoking simultaneity, or if the issue of simultaneity itself is not relevant, then this standard may not 

apply [4].

2. Analysis 

2.1. An analysis of the impressions must occur before concluding simultaneity [2, 3, 5]. The analysis 

shall include (1) the determination whether the friction ridge impressions are consistent with a 

simultaneous impression and (2) the determination whether each friction ridge impression within 

the simultaneous impression stands alone or must be compared in the aggregate. The term “stand 

alone” means that a conclusion of individualization for a single impression can be reached 

independently of other impressions within the aggregate. 

2.2. Analysis of two or more friction ridge impressions as a simultaneous impression

2.2.1. The following factors for each friction ridge impression and the aggregate shall be analyzed 

to confirm or refute that the impressions are consistent with having been deposited 

concurrently: 

2.2.1.1. The object(s) upon which the friction ridge impressions exist.

Determine that one or more friction ridge impressions are present on a single or 

multiple objects (Figures 1 – 4). 

Figure1: Simultaneous impression on a single surface.

Figure 2: Simultaneous impression with a void due to substrate gap (shape of the revolver in this image).
Document #20 Standard Simultaneous Impression 

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Figure 3: Simultaneous impression across a semi-porous surface (label) and a nonporous surface (plastic).

Figure 4: Simultaneous impression across two pieces of paper.
Document #20 Standard Simultaneous Impression 

Examinations, Ver. 2.0

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2.2.1.2. Orientation

Determine that the orientation is consistent between (1) friction ridge 

impressions within the aggregate, (2) each friction ridge impression and the 

hand or foot morphology, and (3) the hand or foot morphology and the object.

2.2.1.3. Spatial relationship 

Determine that each friction ridge impression within the aggregate is within 

anatomical spatial tolerances of the hand or foot with the object(s). 

2.2.1.4. Substrate (surface) 

2.2.1.4.1. Determine that the aggregate of the friction ridge impressions is 

consistent with the surface(s) on which it appears. Substrate examples 

are as follows:

2.2.1.4.1.1. A single surface such as one side of a piece of paper on 

which all friction ridge impressions appear. 

2.2.1.4.1.2. Two surfaces such as opposite sides of a piece of paper 

with one or more friction ridge impressions appearing on 

each side, such as a thumb print on the corner of one 

side and the index and middle finger on the other side.

2.2.1.4.1.3. Two different surfaces on a single object, such as the 

paper label on a glass bottle; one fingerprint on the 

paper label and two fingerprints on the glass bottle. 

2.2.1.4.1.4. Two surfaces on two objects, such as two pieces of 

overlapped paper on which the fingerprints appear on 

one and the lower joints and a partial palm print appear 

on the other. 

2.2.1.5. Friction ridge skin features and anatomical features

2.2.1.5.1. Determine that the friction ridge skin features, for example ridge width, 

ridge flow, and creases, are consistent with simultaneity.

2.2.1.5.2. Determine that the anatomical features, for example finger height, toe 

span, and impression size are consistent with simultaneity. 

2.2.1.6. Processing technique and matrix

Determine that each friction ridge impression within the aggregate has similar and 

consistent appearance for the matrix or specific processing technique(s) used to 

visualize it.

2.2.1.7. Distortion

2.2.1.7.1. Determine that the friction ridge impressions have consistent 

appearance insofar as deposition pressure, lateral pressure, and 

twisting (Figure 1). 

2.2.1.7.2. Determine that the distortion(s) within the aggregate of the friction ridge 

impressions exhibit consistent appearance for the object and substrate.

2.3. Simultaneous impression determination

2.3.1. In determining whether two or more friction ridge impressions are a simultaneous impression 

the examiner must consider each factor listed in 2.2, individually and in the aggregate. The 

analysis of the applicable factors must support or refute the determination of simultaneity. The 

outcome of this analysis will result in one of the following scenarios: 
Document #20 Standard Simultaneous Impression 

Examinations, Ver. 2.0

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2.3.1.1. All friction ridge impressions are consistent with having been deposited concurrently, 

and as such, are considered to be a simultaneous impression.

2.3.1.2. A subset of the friction ridge impressions are consistent with having been deposited 

concurrently, and the subset is considered to be a simultaneous impression.

2.3.1.3. None of the friction ridge impressions are consistent with being deposited 

concurrently, and as such, are not considered to be a simultaneous impression.

2.3.1.4. Simultaneity cannot be supported or refuted.

2.4. Simultaneous impression assessment

2.4.1. Each individual impression within the aggregate must be analyzed and will result in one of the 

following scenarios:

2.4.1.1. All friction ridge impressions stand-alone (Figure 5).

Figure 5: Simultaneous impression where all impressions stand-alone.

2.4.1.2. One or more, but not all, of the friction ridge impressions will stand-alone. Those 

friction ridge impressions which do not stand-alone must be compared in the 

aggregate in order to reach a conclusion (Figure 6).

Figure 6: Simultaneous impression with three impressions that stand-alone and one impression that must be 

compared in the aggregate. The far right impression must be compared in the aggregate.
Document #20 Standard Simultaneous Impression 

Examinations, Ver. 2.0

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2.4.1.3. At least one of the friction ridge impressions will stand-alone and at least one of the 

remaining friction ridge impressions only provides anatomical or spatial information.

Friction ridge impressions that do not stand-alone may be compared in the 

aggregate in order to reach a conclusion, whereas those providing anatomical or 

spatial information may be used to support or refute simultaneity (Figure 7).

Figure 7: Simultaneous impression with two impressions that stand-alone (2 on left), one impression that must be 

compared in the aggregate (2nd from right), and one impression that only supports simultaneity (far right).

2.4.1.4. None of the friction ridge impressions stand-alone so all of them must be compared 

in the aggregate to reach a conclusion (Figure 8).

Figure 8: Simultaneous impression where all of the impressions must be compared in the aggregate.

2.4.1.5. None of the friction ridge impressions stand-alone and some of them provide only 

anatomical or spatial information. Those providing anatomical or spatial information 

may be used to support or refute simultaneity, whereas the remaining impressions 

may be used in the aggregate for reaching a conclusion (Figure 9).
Document #20 Standard Simultaneous Impression 

Examinations, Ver. 2.0

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Figure 9: Simultaneous impression with two impressions that must be compared in the aggregate (two on right) 

and one impression that only supports simultaneity (far left).

2.4.1.6. The impressions may provide only anatomical or spatial information (Figure 10).

Figure 10

3. Comparison of Simultaneous Impression(s)

3.1. Prior to comparison, an analysis of the known exemplars must be performed ensuring that all 

impressions are in proper sequence and attributable to the same person.

3.2. For each friction ridge impression determined to be of value, the examiner should proceed to the 

comparison phase.
Document #20 Standard Simultaneous Impression 

Examinations, Ver. 2.0

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3.3. Simultaneity can be supported or refuted during the comparison, evaluation, or verification phase. If it is 

refuted then re-analysis shall occur.

4. Evaluation of Simultaneous Impression(s)

4.1. For each of the scenarios provided in 2.4, an evaluation conclusion can support or refute simultaneity.

If simultaneity is refuted, re-analysis is required. If the impressions are consistent with simultaneity, 

standards for conclusions are applied to the impression in the aggregate. Friction ridge impressions 

that do not stand-alone must be compared in the aggregate in order to reach a conclusion.

4.2. For a conclusion of individualization, the details contained within all friction ridge impressions must be 

in agreement across all corresponding impressions.

5. Verification of Simultaneous Impression(s)

5.1. When a conclusion is based on simultaneity:

5.1.1. The determination of simultaneity for the impression shall be verified.

5.1.2. The conclusion of individualization shall be verified.

5.1.3. The conclusion of exclusion or inconclusive should be verified.

5.2. Conflicts shall be addressed within the agency’s conflict resolution process.

5.3. Blind verification should be utilized where none of the impressions within a simultaneous impression 

stand-alone [7].

6. Documentation of Simultaneous Impression(s)

6.1. Case note documentation should reflect the ACE-V methodology as it applies to the simultaneous 

impression examination. 

6.2. Documentation of analysis

6.2.1. For each applicable analysis factor listed under section 2.2, the case note documentation shall 

reflect the pertinent information. This information shall be documented by a photograph, lift, or 

legible copy with sufficient annotation in the written examiner notes for another competent 

examiner to interpret what was done, and allow replication of the analysis decision.

6.2.2. For each analysis factor that supports simultaneity under section 2.2, it may be necessary to 

document factual case information or qualitative information derived during the analysis.

6.2.2.1. An example of factual case information is knowledge that the object is a bottle 

because the examiner personally processed it.

6.2.2.2. An example of qualitative information derived by the examiner is the presence and 

consistency of lateral pressure in a friction ridge impression or across all 

impressions.

6.2.3. Due to circumstances of touch, there may be factors that should be documented other than 

those listed under analysis section 2.2.

6.2.4. For each friction ridge impression within a simultaneous impression the orientation, spatial 

relationship, and anatomical features shall be captured using an annotated photograph, lift, or 

legible copy. Each agency performing simultaneous impression examinations should establish 

a policy for consistent annotation of simultaneous impressions. The following examples 

demonstrate some of the various ways that these annotations can be made.

6.2.4.1. Distal segment of the fingerprints

Draw a horseshoe-shaped mark over the top of the distal segment of the fingerprint 

using one continuous line connecting all the fingerprints (Figure 11).
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Examinations, Ver. 2.0

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Figure 11

6.2.4.2. Proximal and medial segments (commonly known as lower joints) of fingerprints 

Draw one line on each side of the proximal and medial segments with the notation 

"LJ" indicating it is a lower joint. Draw one lower line to connect all LJ impressions 

(Figure 12).

Figure 12

6.2.4.3. Distal, proximal, and medial segments of fingerprints and palmprint

Draw a horseshoe-shaped mark over the top of the fingerprints using one 

continuous line connecting all the fingerprints. Draw a bracket at the bottom of the 

palm print. Draw one line on the hypothenar or thenar side to connect the palm print 

to the fingerprints or lower joint(s) (Figures 13 & 14).
Document #20 Standard Simultaneous Impression 

Examinations, Ver. 2.0

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Figure 13
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Figure 14

6.2.4.4. Toeprint and footprint 

Same as fingerprints and palmprints but include footprints or toeprints as notation 

(Figures 15 & 16).
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Figure 15
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Figure 16

6.2.5. For each separate friction ridge impression contained within the simultaneous impression, the 

case note documentation, either in writing or annotations on a photograph, lift, or legible copy 

must reflect whether the impression (1) is part of an aggregate, or (2) provides only anatomical 

or spatial information but supports the simultaneity decision.

6.2.5.1. Friction ridge impressions that stand-alone need not be labeled as such (Figure 17).

Figure 17

6.2.5.2. Friction ridge impressions of value for comparison that do not stand-alone but require 

the aggregate of all impressions must be labeled as an aggregate (e.g., “AGG”) (Figure 

18).
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Figure 18

6.2.5.3. Friction ridge impressions that are considered as being of value for supporting 

simultaneity but are considered of no value for comparison should be noted as no 

value (e.g., “NV”- Figure 19).

Figure 19

6.2.6. For each friction ridge impression deemed to be of value for comparison, the detail relied upon 

in reaching that determination should be documented. This may be done using annotated 

photographs, lifts, legible copies, or other case notes. This information may be annotated as 

“analysis” data (Figure 20).
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Figure 20

6.2.7. Other impressions of value present on the lift or photograph that are not within the annotated 

simultaneous impression are marked separately and not joined to the aggregate.

6.3. Documentation of comparison

6.3.1. For each simultaneous impression, the case documentation must reflect all comparisons 

conducted with known exemplars by name or unique identifier.

6.3.2. A simultaneous impression compared with other simultaneous impressions (latent prints to 

latent prints) must also be documented.

6.3.3. For each friction ridge impression deemed of value for comparison, the detail relied upon 

during the comparison should be documented. This may be done using annotated 

photographs, lifts, legible copies, or other case notes. This information may be annotated as 

“comparison” data (Figure 21).

Figure 21
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6.3.4. This documentation may be different than set forth in the analysis photograph and would 

require separate and additional documentation, for example, a second photograph. If it is not 

different, then the documentation can be modified by adding the “comparison” annotation.

6.4. Documentation of evaluation

6.4.1. Each simultaneous impression will require case documentation of the conclusion reached 

when compared with a known exemplar or other latent impression. The Standard for 

Examining Friction Ridge Impressions and Resulting Conclusions [4] and Standard for a 

Quality Assurance Program in Friction Ridge Examinations [7] shall be followed. The 

documentation must enable a reviewer to associate each impression with the comparisons 

conducted and conclusions rendered.

6.4.1.1. Individualization

Document the name or unique identifier of the person identified, along with the 

respective finger or palm designation, in the case record. The case record shall 

include annotated photographs, lifts, legible copies, or other notes (Figure 22).

Figure 22

6.4.1.2. Exclusion 

Document the name or unique identifier of the person in the case record.

6.4.1.3. Inconclusive

Document the name or unique identifier of the person in the case record (Figure 23).

Figure 23

6.5. Documentation of Verification

6.5.1. Verification documentation should be made on an unmarked photograph or legible copy and 

also recorded in the case record.

6.5.2. The case record shall reflect the conclusions and name or initials of the verifying examiner.
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7. Reporting of Simultaneous Impression(s)

7.1. Individualizations where none of the impressions within the aggregate stand-alone shall be reported as 

a simultaneous impression.

7.2. Simultaneous impression(s) where one or more of the impressions within the aggregate stand-alone

may be reported as simultaneous depending on how the impression relates to the circumstances of the 

touch.

7.3. Report wording examples are included in the Appendix.

8. References

[1] Ashbaugh, D. R. Quantitative-Qualitative Friction Ridge Analysis: An Introduction to Basic and Advanced 

Ridgeology; CRC Press LLC: Boca Raton, FL, 1999, 134-135. 

[2] Cowger, J. F. Friction Ridge Skin; CRC Press LLC: Boca Raton, FL, 1993, 154-156.

[3] Wein L. M. and Baveja M. (2005) "Using fingerprint image quality to improve the identification performance 

of the U.S. Visitor and Immigrant Status Indicator Technology Program", Proceedings of the National 

Academy of Science of the United States of America, 102(21), pp. 7772–7775. 

[4] SWGFAST, Standards for Examining Friction Ridge Impressions and Resulting Conclusions, 9/13/11, 

ver.1.1.

[5] Wisniewski, P. Comparison of Fingerprints Recovered in a Composite Way. Problemy Kryminalistyki. 

2003, 239, 21-29.

[6] Black, J. P. Pilot Study: The Application of ACE-V to Simultaneous (Cluster) Impressions. Journal of 

Forensic Identification. 2006, 56 (6), 933 - 971. 

[7] SWGFAST, Standard for a Quality Assurance Program in Friction Ridge Examinations, 9/11/12, ver. 5.0.

9. Further Reading

Budowle, B., Buscaglia, J., and Perlman, R. Review of the Scientific Basis for Friction Ridge Comparisons as 

a Means of Identification: Committee Findings and Recommendations. Forensic Science Communications. 

2006, 8 (1). 

Gaudes, C. Digit Determination. Identification Canada. 2002, 25 (4), 11-15. 

Ostrowski, S. Simultaneous Impressions: Revisiting the Controversy. The Weekly Detail #13. www.clpex.com. 

November 5, 2001 (accessed September 2007). 

An Analysis of Standards in Fingerprint Identification. FBI Law Enforcement Bulletin. 1972 46 (6), 1-6. 

Method for Fingerprint Identification. Part II: Detailing the method using common terminology and through the 

definition and application of shared principles. Interpol European Expert Group on Fingerprint Identification. 

www.interpol.int/Public/Forensic/fingerprints/WorkingParties/IEEGFI2/default.asp (accessed October 30, 

2007).
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Appendix

The following are examples for different methods of reporting a simultaneous impression. These examples 

include multiple scenarios of individualized simultaneous impressions. 

• A simultaneous impression containing three latent fingerprints has been detected on Q1. The 

simultaneous impression has been individualized with JOHN DOE.

• A simultaneous impression containing one latent fingerprint and one latent palm print of value for 

comparison has been detected on Q1. The simultaneous impression has been individualized with 

JOHN DOE. 

• Examination of Exhibit 1 revealed one simultaneous impression consisting of three latent fingerprints, 

each suitable for identification, designated L-1, L-2 and L-3. The simultaneous impression was 

individualized as the right index, right middle and right ring fingerprints, respectively, of the person whose 

record fingerprints are marked “Exhibit 2 - JOHN DOE.” 

• Examination of Exhibit 1 revealed one simultaneous impression of value for comparison consisting of 

three latent fingerprints designated collectively as L-1. The simultaneous impression, in the aggregate, 

was individualized as the right index, right middle and right ring fingerprints, of the person whose record 

fingerprints are marked “Exhibit 2 - JOHN DOE.” 

• Examination of the shovel (Exhibit 1) revealed three identifiable latent fingerprints consistent with 

simultaneous deposition (one touch) on the shovel handle. JOHN DOE made the three latent 

fingerprints on the shovel handle. 

• Examination of Exhibit 1 revealed one simultaneous impression consisting of three latent fingerprints 

designated L-1. The simultaneous impression was individualized as the right index, right middle and right 

ring fingerprints of the person whose record fingerprints are marked “Exhibit 2 - JOHN DOE.” 

This example is for a simultaneous impression that is not suitable for individualization. 

• A simultaneous impression of the right hand consisting of three fingers and a partial palm deposited in 

apparent dried blood has been detected on the axe handle of Exhibit Q1. It has been determined to be 

of no value for individualization but may be of value for exclusion. Photographs of the impression are on 

file for comparison with any record prints that may be submitted. 
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10. Revision Table

Version Effective Start Effective End Posted Archived Change

1.0 09/12/08 11/17/12 09/12/08 11/17/12 Original issue

2.0 11/17/12 N/A 12/24/12 N/A Updated version

Reformatted (start of new 

version number)