Status Update

Friction Ridge Subcommittee

SAC Physics/Pattern

Henry Swofford

August 12, 2019
1. Provide baseline requirements to 

ensure friction ridge examinations 

are valid as applied

2. Provide “best practice 

recommendations” to ensure 

friction ridge examinations are 

reliable

3. Promote efforts to standardize

the discipline across units and 

jurisdictions

Strategic Roadmap

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Subcommittee Leadership

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• Chair: Henry Swofford

• HJS Consulting, LLC

• Term expiration September 30, 2020

• Email: hswofford@Hotmail.com

• Vice Chair: Thomas Wortman

• Defense Forensic Science Center

• Term expiration September 30, 2021

• Email: Thomas.M.Wortman.Civ@mail.mil

• Executive Secretary: Maria Ruggiero

• Los Angeles County Sheriff’s Office

• Term expiration September 30, 2019

• Email: mcruggie@lasd.org
Subcommittee Breakdown

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Category Target Current

Practitioner Total 14 70% 15 75%

Federal 4 20% 2 10%

State and Local 6 30% 9 45%

Civil and Other 4 20% 4 20%

Researchers and Scientists 4 20% 5 25%

R&D Technology 2 10% 0 0%
Subcommittee Membership

• Black, John P. Black & White Forensics, LLC 2021 john@bwforensics.com 

• Brock, Steven Santa Clara County Sheriff's Office 2021 Steve.Brock@shf.sccgov.org

• Cole, Simon University of California – Irvine 2021 scole@uci.edu

• Connelly, Joshua Douglas County Sheriff 2019 joshua.connelly@douglascounty-ne.gov

• Eldridge, Heidi RTI 2019 heidi.eldridge@icloud.com 

• Small, Liz FBI Laboratory 2020 eksmall@fbi.gov 

• Hall, Carey Minnesota Bureau of Criminal Apprehension 2019 carey.hall@state.mn.us

• Hornickel, Mandi Illinois State Police 2020 Mandi.Hornickel@illinois.gov

• Kriel, Louis Georgia Bureau of Investigation 2020 louis.kriel@gbi.ga.gov 

• Cuellar, Maria University of Pennsylvania 2021 mcuellar@sas.upenn.edu

• Pacejka, Andrew Utah Bureau of Forensic Services 2021 apacejka@utah.gov

• Ruggiero, Maria C. Los Angeles County Sheriff's Department 2019 mcruggie@lasd.org

• Schwarz, Matthew T. Schwarz Forensic Enterprises, Inc. 2019 matt@schwarzforensic.com 

• Smith, Ron Ron Smith & Associates, Inc. 2020 ron@ronsmithandassociates.com 

• Speckels, Carl City of Phoenix Crime Laboratory 2020 carl.speckels@phoenix.gov 

• Swofford, Henry J. HJS Consulting, LLC 2020 hswofford@Hotmail.com

• Tabassi, Elham National Institute of Standards and Technology 2021 elham.tabassi@nist.gov 

• White, Alice Evolve Forensics, LLC 2020 alicevirginiawhite@gmail.com

• Wortman, Thomas M. Defense Forensic Science Center 2021 thomas.m.wortman.civ@mail.mil 

• Zinn, Lisa M. Orange County Sheriff's Crime Laboratory 2019 lzinn@occl.ocgov.com 

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Roadmap

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Personnel

Quality Assurance

Testing/Examination

Focus

• Current Strategic Priority:

• Promulgation of standards and guidelines related to the examination, 

interpretation, and reporting of friction ridge evidence
Documents Completed (at SDO)

✓*ACE-V Process Map

✓*Best Practice Recommendation for Conflict Resolution

✓*Best Practice Recommendation for Verification

✓*Best Practice Recommendation for Technical Review

✓Standard for Friction Ridge Examination Conclusions

✓ Standard for Friction Ridge Examination Training

✓Guideline for the Articulation of the Decision-Making 

Process Leading to an Expert Opinion of Source 

Identification in Friction Ridge Examinations

• Document drafts publically available online:

• https://www.nist.gov/topics/forensic-science/friction-ridge-subcommittee

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Update → Standard for Conclusions

• Defines terms and qualitative expressions of source 

conclusions that may be reached following friction ridge 

comparisons.

• Five conclusion scale

• Source Exclusion

• Support for different sources

• Inconclusive/Lacking Support 

• Support for same source

• Source Identification

• Source Identification:

• Strongest degree of association between two friction ridge impressions

• Expressed as a “strength of evidence” statement

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Update → Standard for Conclusions

• Source Identification: The strongest degree of association between 

two friction ridge impressions. It is the conclusion that the observations 

provide extremely strong support for the proposition that the 

impressions originated from the same source and extremely weak 

support for the proposition that the impressions originated from different 

sources.

• Source Identification is reached when the friction ridge impressions 

have corresponding ridge detail and the examiner would not expect to 

see the same arrangement of details repeated in an impression that 

came from a different source.

• Qualifications & Limitations: An examiner shall not assert that a 

source identification is the conclusion that two impressions were made 

by the same source or imply an individualization to the exclusion of all 

other sources.

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Update → ACE-V Process Map

• Provides an interactive business process map illustrating the process of 

conducting friction ridge impression examinations.

• Salient Features:

• Provides an interactive and illustrative interface for the friction ridge community

• Codifies current practice (including various methods, approaches, and 

applications)

• Identifies gaps and research needs for future practice

• Dynamic document updating as the standards and best practices update

• NOTE: This process map is NOT an endorsement for methods. It is an 

illustration of the various ways friction ridge examinations are conducted 

today around the country. This map is a living document that will be 

updated as the OSAC moves toward standardizing a single way forward.

DISCLAIMER: Document is in DRAFT form and subject to change prior to release.

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Update → Conflict Resolution

• Describes the best practice recommendations for how 

to resolve conflicts between examiners during 

Verification or Technical Review:

• Remediating Interaction

• Managerial discretion:

• Blind verification

• Consensus opinion

• Outside agency examination

• Documentation shall include:

• All examiner conclusions

• Images with markups of features observed to support decision/opinion

• Date examined

• Results of examination

• Any changes of decision/opinion

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Update → Verification

• Describes the best practice recommendations for how to perform the 

verification steps during friction ridge impression examinations.

• Verification considerations (e.g. extent, utility, case type, approach)

• Types of verification and application options

• Documentation 

• Salient Features:

• Verification should include an independent examination by another 

competent examiner (e.g. re-application of A-C-E)

• Verification should apply to ALL decisions, including utility (suitability) 

decisions and examination conclusions

• No studies exist on whether blind verification will detect more errors; 

however, general scientific literature suggests blind verification is a better 

approach.

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Update → Technical Review

• Describes the best practice recommendations for how to 

perform the technical review of friction ridge impression 

examinations.

• Salient Features:

• Technical review should occur in every case

• Labs shall have a policy defining what is required in technical review

• Technical review shall be documented in the case record

• Labs shall have a policy to address non-conforming work

• Non-conforming work shall be documented in the case record

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Documents in Progress

• Examination Method 

• Analysis 

• Comparison/Evaluation

• Consultation

• Reporting Results

• ABIS Best Practices

• Terminology

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In Progress → Examination Method

• Prescribes minimum requirements for how examinations shall be conducted, 

documented, and justified based on clearly demonstrable and articulable 

criteria. 

• Salient Features:

• Labs shall have a procedure to define utility decisions and the criteria necessary to 

support (based on observed data)

• Labs shall have a procedure to document the observed data relied upon to support 

utility decision

• Labs shall have a procedure to define “complex” impressions, and required 

documentation for complex vs. non-complex.

• Labs shall have a procedure to define the criteria necessary to support each source 

conclusion

• Labs shall have a procedure to document observed data used to support the 

conclusion and changes in interpretations after exposure to the known impression

• Labs shall have a procedure for routinely monitoring examiners’ ability to detect 

features, determine suitability, formulate source conclusions.

DISCLAIMER: Document is in DRAFT form and subject to change prior to release to the SDO.

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In Progress → Analysis BPR

• Describes the best practice recommendations for how to 

perform the analysis steps during the examination of friction 

ridge impressions.

• Salient Features:

• Utility/Suitability criteria (e.g. how much is enough?)

• Feature selection and documentation of associated confidence

• Complexity criteria (e.g. when is an impression “complex”)

• Digital documentation recommended 

DISCLAIMER: Document is in DRAFT form and subject to change prior to release to the SDO.

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In Progress → Comparison & 

Evaluation BPR

• Describes the best practice recommendations for how to perform the 

comparison and evaluation steps during the examination of friction 

ridge impressions.

• Salient Features:

• Method of comparison

• Complex comparison criteria

• Sufficiency criteria for conclusions (e.g. how much is enough?)

• Assessment of similar and dissimilar characteristics between impressions

• Assessment of the strength of the evidence

• Determination of the appropriate conclusion

• Documentation 

DISCLAIMER: Document is in DRAFT form and subject to change prior to release to 

the SDO.

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In Progress → Standard for 

Consultation

• Describes the minimum requirements for how to perform consultations 

during friction ridge impression examinations.

• Salient Features:

• Preliminary observations shall be recorded prior to consultation (and shall not be 

provided to consulting examiner beforehand)

• Consultation related to the following shall be documented:

• Assessment of utility for comparison

• Assessment of utility for AFIS search

• Presence/absence of specific features during Analysis or Comparison

• Simultaneity of Impressions

• Assessment of complexity

• For complex comparisons, a separate set of notes, annotations, or images generated 

by the consultant should be included in the case record.

DISCLAIMER: Document is in DRAFT form and subject to change prior to release to the SDO.

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In Progress → Standard for 

Reporting Results

• Prescribes the minimum requirements that shall be included in friction ridge 

examination reports.

• Salient Features:

• Method used to perform examination

• Any deviations from approved methods, policies, procedures

• Assumptions and limitations of any methods or procedures used to produce results

• Statement if examinations were conducted, ABIS databases searched (and which ones)

• Only comparisons which have been conducted shall be reported (e.g. must have actually 

done a comparison to render an exclusion)

• Inconclusive/Lacking Support shall include a reason

• Manner of expressing conclusions:

• Expert opinion based on knowledge, training, and experience (KTE)

• Expert opinion based on use of KTE and quantitative support from probabilistic models

• Conclusions derived directly from and entirely dependent upon probability models

DISCLAIMER: Document is in DRAFT form and subject to change prior to release to the SDO.

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In Progress → ABIS Best Practices

• Describes the best practice recommendations for effective uses of 

Automated Biometric Identification Systems (ABIS):

• Salient Features

• Provides guidance to latent print and tenprint units

• Stimulates further development of advanced capabilities by ABIS vendors

• Addresses improvements to facilitate interoperability, including:

• Acquisition of standards-compliant systems at the Federal, State and Local-Levels

• Furthering connectivity efforts among law enforcement agencies

• Improved governance structures to reflect the new interoperable environment

• Developing mechanisms to test system performance and standards compliance

• Expanded examiner training

• Other ABIS related topics to improve performance and efficiency of 

friction ridge examinations

DISCLAIMER: Document is in DRAFT form and subject to change prior to release to the SDO.

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In Progress → Terminology

• Describes the terms and definitions commonly used by the 

friction ridge examination discipline.

• Salient Features:

• Intended to reside in the OSAC Lexicon Library

• Intended to be dynamic and updated as appropriate

• Searchable for easy user interface

• Will be adapted from ISO/IEC 9000, 17025, or 17020, where practical

DISCLAIMER: Document is in DRAFT form and subject to change prior to release to 

the SDO.

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Current Research Needs

• ACE-V Bias

• Assessing the Sufficiency and Strength of Friction Ridge 

Features

• Close Non-Match Assessment

• Examiner Consistency During Friction Ridge Feature Mark-Up

• Friction Ridge Statistical Modeling

• Latent Fingerprint Image Quality Usage

• Research needs publically available online:

• https://www.nist.gov/topics/forensic-science/osac-researchdevelopment-needs

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Additional Items of Interest

✓ OSAC FRS Response to PCAST

✓ OSAC FRS Response to the DoJ Proposed Uniform Language 

for Testimony and Reports

✓ OSAC FRS Response to the DoJ Forensic Science Discipline 

Reviews

✓ Discipline-Specific Baseline Documents (i.e. legacy SWGFAST 

documents)

• Documents publically available online:

• https://www.nist.gov/topics/forensic-science/friction-ridgesubcommittee

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General Process

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FRSC TG: 3-5 FRSC: 20

PSAC: 15

RCs: 62

FRSC: 20 PSAC: 15 SDO

QIRC: 15

HFC: 11 LRC: 11

STG: 25

FRSC: 20
Visit us online!

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https://www.nist.gov/topics/forensic-science/friction-ridge-subcommittee