UNIVERSITY OF VIRGINIA 

 

Latent Fingerprint Processing

Forensics @ NIST

November 9, 2016
Contributors

CSFAFE/ 

University of Virginia

 Sharon Kelley, JD, PhD

 Daniel Murrie, PhD

 Brandon Garrett, JD

Houston Forensic Science 

Center 

 Alicia Rairden, MS, CLPE

 Amy Castillo, PhD
Objectives/Rationale

 Study case processing of latent prints in large lab (HFSC)

 First, gather basic information about case flow:

 Later, study potential interventions, e.g.:

UNIVERSITY OF VIRGINIA

 

Frequency of verifications

Frequency with which verifications lead to changes in original examiners’ 

conclusions 

Frequency of conflict resolution 

Examiner differences 

Implementation of blind verification 

Blinding analysts to task-irrelevant information

New procedures for conflict resolution 
Baseline, descriptive data:

 Illustrative data regarding case flow

 Such basic data is important, but rarely accessible

 Provides a baseline for comparison: 

 With post-intervention changes at this lab

 With procedures at other labs

 Provides an illustration of self-study (replicable in other labs):

 Rates of verifications and outcomes,

 Examiner differences and conflict resolution,

 Etc. 

UNIVERSITY OF VIRGINIA

 
CASE VOLUME AND INITIAL 

DECISIONS 
Case Volume and Offense Type 

 Case processing data over 2 Years

 Total Number of Cases: 2,536

 Offenses Range from 

 Shoplifting to 

 Capital Murder Burglary, 36%

Robbery, 20%

BMV, 17%

Auto Theft, 8%

Murder, 6%

Theft, 3%

Other, 

7%

• Aggravated Assault, 1%

• Criminal Mischief, 1%

• Possession CDS, 1%

• Outside Auto Theft, 1%
Latent Prints Across 2,536 Cases

 Total Number of Latent Prints Analyzed: 12,363

 Total Number of Latent Prints of Value: 5,430

71%

26%

1% 2%

Prints of Value by Type

Fingerprints

Palm Prints

Joint Imp

Other Imp

44%

56%

Relative Proportion of Value and 

No Value Prints

Prints of Value

Prints of No Value
Latent Prints by Offense Type
Distribution of Latent Prints Across 

Cases

 Range: 1-153 prints

 Mean: 8.50 Median: 4.00 Mode: 1

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8 9 10

Number of Cases

Number of Prints
Initial Examiner Decisions for Latents 

of Value

 N = 12,363 Latent Prints

60%

28%

11% 1%

Decisions About Latents 

of Value

Identifications

Exclusions

Inconclusive

(Exemplar)

Inconclusive

(Latent)

44%

56%

Relative Proportion of Value 

and No Value Prints

Prints of Value

Prints of No Value
Overall Decisions 

Prints of No 

Value

Identifications 56%

26%

Exclusions

13%

Inconclusive 

(exemplar)

5%

Inconclusive 

(latent)

0%
VERIFICATION AND 

CONSULTATION 
Verification Policy

 Primarily based on offense type 

 Generally:

 Violent Offenses: All decisions verified 

 Property Offenses: Only identifications verified 
Verification and Consultation

N = 2,536 Cases 

3% of all cases 

proceed to 

Consultation 

•  During Verification, analysts 

agree 93% of the time

7% (n = 82) of cases 

that have been 

verified proceed to 

Consultation 

No 

Verification

Only ID 56%

8%

Verification 

36%

n = 1418

n = 913

n = 204
Results of Consultation 

 82 cases, 132 prints 

 Final decisions are typically those of 

the verifier as opposed to original

analyst 

Analyst

28%

Verifier 

72%
Post-Consultation Decisions: 

Value/No Value 

Conclusion Frequency Conclusion Changed 

During Consultation 

Latent of No Value 

Latent of Value

18 Yes

Latent of Value  Latent 

of No Value

14 Yes 

Latent of Value Remains 8 No

Latent of No Value 

Remains

3 No
Post-Consultation Decisions: 

Identification/Inconclusive/Exclusion

Conclusion Frequency Conclusion Changed During 

Consultation 

Exclusion  Identification 22 Yes

Exclusion  Inconclusive 15 Yes

Identification 

Inconclusive

14 Yes 

Identification Remains 

(vs. Inconclusive)

13 No

Inconclusive 

Identification

12 Yes

Inconclusive  Exclusion 10 Yes 

Inconclusive Remains 

(vs. Identification)

2 No

Exclusion Remains 

(vs. Inconclusive)

1 No 
CONFLICT RESOLUTION 
Conflict Resolution

 8 Cases, 10 prints 

Conclusion Frequency Conclusion Changed During 

Conflict Resolution

Latent of Value  Latent of 

No Value

2 Yes

No Value Remains 2 No 

Identification 

Inconclusive

1 Yes 

Identification Remains 

(vs. Inconclusive)

1 No

Inconclusive 

Identification

2 Yes

Inconclusive Remains 

(vs. Identification)

1 No

Exclusion Remains 

(vs. Inconclusive)

1 No 
EXAMINER DIFFERENCES
Examiner Differences

 12 Examiners Total 

Domain Range 

Years of Experience 6-28

Cases Verified 29-141

36-63%

Consultations 3-23

1-11%

Decisions Changed During 

Consultation

1-22

33-95%

Conflict Resolution 0-2

(Mode = 0)
Conclusions

Baseline Data  Relevant for comparisons: 

• To other labs

• Post-Intervention 

• E.g., Blind Verifications 

Verification Procedures 

Individual differences 

• Emphasis on processes that result in individual differences

• Intersection with print quality and human factors research 

More data are needed!