RESEARCH STUDY FOR THE
RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND
REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Igor Pacheco, CLPE (Miami-Dade Police Department)
Brian Cerchiai, CTPE (Miami-Dade Police Department)
Stephanie Stoiloff, M.S. (Miami-Dade Police Department)
Sneh Gulati, Ph.D. (Florida International University)
Presented by: Igor Pacheco, CLPE & Brian Cerchiai, CTPE
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS

This project was supported by Award No. 2010-DN-BX-K268
awarded by the National Institute of Justice, Office of Justice
Programs, U. S. Department of Justice.

The opinions, findings, and conclusions or recommendations
expressed in this publication/program/exhibition are those of
the authors and do not necessarily reflect those of the
Department of Justice.
2
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Background

The 2009 National Academy of Sciences’ report titled,
“Strengthening Forensic Science in the United States: A Path
Forward” announced thirteen recommendations to address
challenges facing the forensic science community.
◦ This study was conducted specifically to address concerns of their third
recommendation, “Research is needed to address issues of accuracy, reliability,
and validity in the forensic science disciplines.”

MDPD study was modeled after previous study by Glen Langengurg
◦ Langenburg, G. A Performance Study of the ACE-V Process: A Pilot
Study to Measure the Accuracy, Precision, Reproducibility,
Repeatability, and Biasability of Conclusions Resulting from the ACE-V
process. J. For. Ident., 2009, 59 (2).
3
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Background


Evaluated the reliability of Latent Fingerprint Examiners using the
Analysis, Comparison, Evaluation, and Verification (ACE-V)
methodology in latent fingerprint examinations by
Measured the Accuracy, Precision, Reproducibility, Repeatability, and
Bias of four categorical opinions:
◦ Identification
◦ Exclusion
◦ Inconclusive
◦ No value
4
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Participation

109 Experienced Latent Print Examiners Participated
◦ Requirements to participate:
 1 of active latent casework experience
 uses the ACE-V methodology
 enforcement agency (crime laboratory), or like agency, in the
United States. This includes all active, retired or contracted
latent examiners.
5
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Participants from 75 Different Law Enforcement Agencies
53
Local Agencies
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Participants from 75 Different Law Enforcement Agencies
16
State Agencies
53
Local Agencies
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Participants from 75 Different Law Enforcement Agencies
Federal Agencies
3
16
State Agencies
53
Local Agencies
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Participants from 75 Different Law Enforcement Agencies
Federal Agencies
3
16
State Agencies
4
N/A
53
Local Agencies
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Latent Print Examination Experience
36%
1 – 5 yrs
10
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Latent Print Examination Experience
36%
1 – 5 yrs
14%
5 – 10 yrs
11
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Latent Print Examination Experience
36%
1 – 5 yrs
17%
10 – 15 yrs
14%
5 – 10 yrs
12
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
Latent Print Examination Experience
33%
> 15 yrs
17%
10 – 15 yrs
36%
1 – 5 yrs
14%
5 – 10 yrs
13
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Announcement & Questionnaire
IAI Latent Print Certification
55.05%
Not Certified
44.95%
Certified
14
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Research Questions
1) Will Latent Examiners be able to correctly identify or exclude unknown latent
impressions from known standards using the ACE methodology?
2) Will Latent Examiners be able to correctly identify or exclude unknown latent
impressions from known standards using the ACE-V methodology?
3) Will Latent Examiners be able to reproduce and repeat conclusions from unknown
latent impressions to known standards using the ACE and ACE-V methodology?
4) Will Latent Examiners be able to reproduce and repeat conclusions from unknown
latent impression to known standards using the ACE-V methodology under high
bias conditions?
15
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS

Research Design and Method
Thirteen confidential volunteer sources were identified


8 Men & 5 Women chosen due to not having their fingerprints or
palmprints in any known AFIS database outside of Miami-Dade
County.
13 sets of Tenprint and Palm Print Standards collected
 2,711 known latent impressions were created (fingers and palms)
 Collected from non-porous flat and curved surfaces (plastic, tile, metal, and glass)
 Processed using black powder and clear tape on white backing cards (scanned and
printed as photos)
 The latent impressions included various sizes, clarity, and levels of distortion
16
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Research Design and Method
 Three (3) Certified Latent Print Examiners independently
evaluated and compared 320 latent prints to the known
standards using a rating scale that was created for this
research.
◦ 80 Latent Prints were chosen for the final test sets

Rating Scales for each latent analysis and comparison:
(Analysis)
Strength of Value of Latent Print
+
(Comparison)
Latent in Agreement with Standard
=
2
Difficulty of Comparison
17
Latent in
Agreement with
Standard
Strength of Value
of Latent Print
Minutiae:
4.33
4.33
Minutiae
Formations: 0.00
0.00
Clarity:
2.00
Total:
0.67
6.33
5.00
Difficulty of Comparison: 5.67
0 Insufficient to Difficult 7
14
21
18
Latent in
Agreement with
Standard
6.00
Strength of Value
of Latent Print
Minutiae:
10.00
Minutiae
Formations: 1.00
0.66
Clarity:
1.33
2.00
12.33
8.66
Total:
0
7
Difficult to Moderate 14
Difficulty of
Comparison:
10.5
21
19
Latent in
Agreement with
Standard
14.00
Strength of Value
of Latent Print
Minutiae:
14.00
Minutiae
Formations: 3.33
3.33
Clarity:
2.00
2.00
19.33
19.33
Total:
Difficulty of Comparison: 19.33
0
7
14 Moderate to Easy
21
20
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Research Design and Method
Distribution of Latent Prints for Testing
30%
24 Latent Prints
Source was not Present
70%
56 Latent Prints
Source was Present
21
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Research Design and Method
Source Not Present: Strength of Value of Latent Print
(24 Latents)
25%
6 Latent Prints
Insufficient to Difficult
22
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Research Design and Method
Source Not Present: Strength of Value of Latent Print
(24 Latents)
37.5%
9 Latent Prints
Moderate to Easy
25%
6 Latent Prints
Insufficient to Difficult
23
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT
EXAMINATIONS
Research Design and Method
Source Not Present: Strength of Value of Latent Print
(24 Latents)
37.5%
9 Latent Prints
Moderate to Easy
25%
6 Latent Prints
Insufficient to Difficult
37.5%
9 Latent Prints
Difficult to Moderate
24
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Research Design and Method
• Study was conducted in 3 Phases over a one year period
Phase 1 (ACE)
Phase 2 (ACE)
Phase 3 (ACE-V)
109 Participants
88 Participants
86 Participants
40 Latent Trials
40 Latent Trials
ACE-V
25 Latent Trials
(Group A)
20 Latent Comparisons
(Group B)
20 Latent Comparisons
Repeatability
27 Latent Trials
High Bias ACE-V
37 Latent Trials
High Bias Repeatability
24 Latent Trials
25
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Research Design and Method
• Phase 1 and 2– 80 Latent ACE Trials
• For each latent trial, participants were asked to conduct an
analysis, comparison and evaluation
• Analysis: Rate clarity, identify anatomical source, certainty
of orientation, and whether the impression was of value or
of no value.
• Comparison: Compare to 3 of the 10 sets of standards that
were provided.
• Evaluation: For each evaluation, the participants were to
indicate whether they had made an identification, an
exclusion, or an inconclusive decision.
26
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Research Design and Method
• Phase 1and 2– 80 Latent ACE Trials
• Answer Sheets
27
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 1 and 2 ACE Trials – Analysis
Value and No Value Decisions
Phase 1
109
Participants
Phase 2
88
Participants
Total Decisions:
Value
3210
1342
4452
No Value
1023
388
1411
Total Decisions:
4233
1730
5963
28
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 1 and 2 ACE Trials – Results
Value and No Value Decisions (5,963)
• 2,457 Correct Identifications
• 953 Correct Exclusions
• 42 Erroneous Identifications
• 235 Erroneous Exclusions
• 446 Inconclusives when from the same source
• 403 Inconclusives when from different sources
29
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 1 and 2 ACE Trials
Error Rates
• False Positive Rate
•Percentage of the time the participant made an erroneous
identification when given the possibility of making any of the three
categorical opinions (Identification, Inconclusive, and Exclusion).
With Inconclusives
Without Inconclusives
3.0%
4.2%
The accuracy of ACE and ACE-V examinations are reported as an overall participant error rate after
participants made a sufficiency determination that a latent was of “value” for Identification.
30
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 1 and 2 ACE Trials – Results
42 Erroneous Identifications
• 35 Erroneous IDs – Appear to be Clerical Errors
Made by 4 different Examiners
• 19 times correct standards but opposite finger or opposite palm was
chosen
• 8 times correct standards and not opposite finger was chosen
• 8 times incorrect standards but same finger or palm was chosen
• 4 Erroneous IDs - Don’t appear to be Clerical Errors
• 4 times incorrect standard and not opposite finger was chosen
• 3 Erroneous IDs the source was not present
• Based on 2 Latent Prints
31
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 1 and 2 ACE Trials – Results
3 Erroneous IDs the source was not present
Latent Print #1
Strength of Value
of Latent:
17.00
Correctly Excluded:
31 times
Erroneously Identified:
1 time
Inconclusive:
8 times
32
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 1 and 2 ACE Trials – Results
3 Erroneous IDs the source was not present
Latent Print #2
Strength of Value
of Latent:
16.00
Correctly Excluded:
33 times
Erroneously Identified:
2 times
Inconclusive:
5 times
33
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 1 and 2 ACE Trials
Error Rates
• False Negative Rate
•Percentage of the time the participant made an erroneous exclusion
when given the possibility of making any of the three categorical
opinions (Identification, Inconclusive, and Exclusion)
With Inconclusives
Without Inconclusives
7.5%
8.7%
34
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Results
(Verification, Bias & Repeatability)
35
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Results
(Verification, Bias & Repeatability)
Phase 3 was comprised of four different groups
•
•
•
•
Group 1 – ACE-V Trials
Group 2 – ACE-V Trials (High Bias)
Group 3 – ACE-V Trials (Repeatability)
Group 4 – ACE-V Trials (Repeatability, High Bias)
36
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Results

ACE-V + Repeatability, Answer Sheet

If your comparison agrees with the identification, please mark the box
labeled "Agree".
37
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Results
• 487 Correct Identifications (agreed with the correct identification)
• 13 Correct Exclusions (disagreed with incorrect identification)
• 0 Erroneous Identifications (agreed with incorrect identification)
• 15 Erroneous Exclusions (disagreed with the correct identification)
• 15 Inconclusives when from the same source
• 2 Inconclusives when from different sources
38
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials
Error Rates
• False Positive Rate
With Inconclusives
Without Inconclusives
0.0%
0.0%
39
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials
Error Rates
• False Negative Rate
With Inconclusives
Without Inconclusives
2.9%
3.0%
40
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Results
 ACE-V + Repeatability, Answer Sheet – High Bias
41
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials (Biased Conditions)– Results
• 178 Correct Identifications (agreed with the correct identification)
• 78 Correct Exclusions (disagreed with incorrect identification)
• 3 Erroneous Identifications (agreed with incorrect identification)
• 15 Erroneous Exclusions (disagreed with the correct identification)
• 51 Inconclusives when from the same source
• 4 Inconclusives when from different sources
42
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials (Biased Conditions)– Results
91.8%
73.0%
20.9%
6.1%
4.7%
3.5%
Correct Identifications
Erroneous Identifications
Agreed
Disagreed
Inconclusive
43
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability
• To determine if the participants would repeat their own conclusions
from comparisons of unknown latent prints to known standards the
results of identification decisions, erroneous exclusions, and
inconclusive results (where the source was present) from Phase 1
were sent to the same participants in Phase 3.
• 27 latent prints latent prints presented to participants for repeatability
• 1,311 participant decisions.
44
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability
45
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability
46
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability
47
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability
48
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability (Biased Conditions)
• To determine if the participants would repeat their own conclusions
from comparisons of unknown latent prints to known standards under
biased conditions, the results of identification decisions, erroneous
exclusions, and inconclusive results (where the source was present)
from Phase 1 were sent to the same participants in Phase 3.
• 24 latent prints latent prints presented to participants for repeatability
under biased conditions
• 333 participant decisions
49
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability (Biased Conditions)
50
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability (Biased Conditions)
1 participant
51
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability (Biased Conditions)
52
RESEARCH STUDY FOR THE RELIABILITY OF THE ACE-V PROCESS:
ACCURACY, PRECISION, REPRODUCIBILITY, AND REPEATABILITY IN LATENT FINGERPRINT EXAMINATIONS
Phase 3 ACE-V Trials – Repeatability (Biased Conditions)
53
Summary of Results
◦
◦
◦
◦
◦
◦
5,963 sufficiency determinations,
4,536 ACE decisions
532 ACE-V decisions
1,311 repeatability decisions,
326 ACE decisions under biased conditions
333 repeatability decisions under biased
conditions
54
Summary of Results
◦ For ACE decisions
 False Positive Rate of 3.0%
 False Negative Rate of 7.5%.
◦ For ACE-V decisions
 Positive Rate of 0%
 False Negative Rate of 2.9%.
55
Summary of Results
◦ Repeatability
 94.6% of the time
previous correct
identifications
repeated
 93.1% of the
time, participants
did not repeat
their previous
erroneous
exclusions
◦ Repeatability -Bias
 73.0% of the time
previous correct
identifications
repeated
 96.5% of the time,
participants did not
repeat their
previous erroneous
exclusions
56
In conclusion…
◦ With respect to this study
 fingerprint examiners are highly accurate and reliable when
conducting examinations using a process that is similar to actual
casework, in which all fingerprint results are verified by a second
fingerprint examiner
 examiners are less likely to miss an identification the easier the latent
print is to compare, and more likely to report an inconclusive
decision when comparing the most difficult latent prints.
 examiners are more likely to miss an identification than to report an
incorrect identification.
 This study indicated that bias may influence decision making. For
example, participants who were asked to perform a second
verification, in which they were given two previous conclusions,
agreed less often with an initial correct identification and reported
more inconclusive decisions.
57
THE END
58