Friction Ridge Subcommittee

Della Wilkinson

OFIA-TPS Conference

30th May 2019
Subcommittee Leadership

2

• Chair: Henry Swofford

• Defense Forensic Science Center

• Term expiration September 30, 2020

• Email: Henry.J.Swofford.Civ@mail.mil

• 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 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 

• Fontaine, Liz FBI Laboratory 2020 ekfontaine@fbi.gov 

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

• Hornickel, Mandi Illinois State Police 2020 Mandi_hornickel@isp.state.il.us 

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

• Lavine, Michael Umass Amhearst 2020 lavine@math.umass.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. Defense Forensic Science Center 2020 Henry.j.Swofford.civ@mail.mil 

• 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 

3
Subcommittee Breakdown

4

Category Target Current

Practitioner Total 14 70% 17 85%

Federal 4 20% 3 15%

State and Local 6 30% 9 45%

Civil and Other 4 20% 3 15%

Researchers and Scientists 4 20% 4 20%

R&D Technology 2 10% 1 5%
Scope

The Friction Ridge Subcommittee will 

focus on standards and guidelines related 

to the forensic examination of friction ridge 

detail from the hands and feet. 

5
Roadmap

6

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)

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

7
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

8
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.

9
Documents in Progress

• Examination Method 

• Analysis 

• Comparison/Evaluation

• Consultation

• Verification

• Technical Review

• Reporting Results

• Conflict Resolution

• ACE-V Process Map

• ABIS Best Practices

• Terminology

10

Image license free for public share and use from pixabay.com
Documents in Progress

Examination Method

• Prescribes minimum requirements of the analysis, comparison, and 

evaluation steps performed during the examination of friction ridge 

impressions, including:

• The set of expected procedures that need to be implemented and their order

• The procedures requiring validation

• The required elements of analysis, comparison, and evaluation

• The required minimum documentation for each procedure

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

to release to the SDO.

11
Documents in Progress

Analysis

• Describes the best practice recommendations for how to perform the 

analysis steps during the examination of friction ridge impressions.

• Suitability criteria

• Feature selection and associated confidence

• Complexity criteria

• Quality criteria

• Documentation 

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

to release to the SDO.

12
Documents in Progress

Comparison & Evaluation

• Describes the best practice recommendations for how to perform the 

comparison and evaluation steps during the examination of friction ridge 

impressions.

• Method of comparison

• Complex comparison criteria

• Sufficiency criteria for conclusions

• 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.

13
Documents in Progress

Consultation

• Describes the best practice recommendations for how to 

perform consultations during friction ridge impression 

examinations.

DISCLAIMER: Document is in DRAFT form and subject to 

change prior to release to the SDO.

14
Documents in Progress

Verification

• Describes the best practice recommendations for how to 

perform the verifications steps during friction ridge impression 

examinations.

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

• Types of verification and application options

• Documentation 

DISCLAIMER: Document is in DRAFT form and subject to 

change prior to release to the SDO.

15
Documents in Progress

Conflict Resolution

• Describes the best practice recommendations for how to 

resolve conflicts between examiners:

• Conflicting suitability decisions

• Conflicting evaluation conclusions

• Documentation

DISCLAIMER: Document is in DRAFT form and subject to 

change prior to release to the SDO.

16
Documents in Progress

ACE-V Process Map

• Provides an interactive business process map illustrating the process of 

conducting friction ridge impression examinations.

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

• Codifies current practice

• Identifies gaps and research needs for future practice

• Dynamic document updating as the standards and best practices update

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

release.

17
Documents in Progress

Terminology

• Describes the terms and definitions commonly used by the 

friction ridge examination discipline.

• Intended to reside in the OSAC Lexicon Library

• Intended to be dynamic and updated as appropriate

• Searchable for easy user interface

DISCLAIMER: Document is in DRAFT form and subject to 

change prior to release to the SDO.

18
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-research- development-needs

19
Additional Items of Interest

 OSAC FRS Response to PCAST

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

documents)

• Documents publically available online:

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

20
General Process

21

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!

22

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