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Monday, March 17, 2008

 
The purpose of the Detail is to help keep you informed of the current state of affairs in the latent print community, to provide an avenue to circulate original fingerprint-related articles, and to announce important events as they happen in our field.
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Breaking NEWz you can UzE...
by Kasey Wertheim (your name could be here!)

Top Judge Chairs New McKie Inquiry MidLothian Today, UK - Mar 14, 2008 ..."A public judicial inquiry into the Shirley McKie fingerprints affair is to be chaired by a top judge from Northern Ireland"...

Government Orders Inquiry Into Shirley McKie Fingerprint Row Daily Record, UK - Mar 14, 2008 ...Supporters of the former detective hope the probe will finally settle the row that plunged Scotland's fingerprints service into crisis...

Osun and Politicisation of Forensic Analysis  Sun News Online, Nigeria,  - Mar 14, 2008 ...inked fingerprint analysis found a 41% fraud rate on Osun State, Nigeria's 250,000 ballots...

Terrorism Prevention: Germany and US agree on Better Data Exchange LifeGen.de, Germany - Mar 11, 2008  ...Data to identify the person (including name, date of birth, nationality, fingerprints) and information substantiating the suspicion of terrorism...

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Announcement: Click link any time for recent, relevant fingerprint NEWS
clpexco 1681 16 Dec 2007 03:36 pm

Evidence Fabrication in South Africa
Pat A. Wertheim 15349 16 Mar 2008 06:06 pm

KEPT - Keeping Examiners Prepared for Testimony
clpexco 1871 16 Mar 2008 02:23 pm

Simultaneous Impressions
Charles Parker 526 16 Mar 2008 01:59 pm

Judge to head fingerprint inquiry
sharon cook 354 16 Mar 2008 11:35 am

Calls for Inquiry to be scrapped
Daktari 18461 14 Mar 2008 03:10 pm

SPR Processing Question
printlady 449 13 Mar 2008 05:09 pm

David Witzke?
Ann Horsman 435 13 Mar 2008 04:02 pm

Error Rate Paper
g. 343 12 Mar 2008 08:41 pm

Fingerprint Society Conference 2008
Taggart 1888 12 Mar 2008 06:41 pm

Cinnamon Toast Crunch Picture
michelleewaldron 414 12 Mar 2008 03:27 pm

Duplicate Lifts
Charles Parker 415 10 Mar 2008 01:52 pm

PRE-EMPLOYMENT TESTS
Ian Rudden 287 10 Mar 2008 12:14 pm


(http://clpex.com/phpBB/viewforum.php?f=2)
 

 
UPDATES ON CLPEX.com


Worked out technical difficulties from re-hosting CLPEX.com to new servers.  I have purchased and installed Microsoft Sharepoint Designer 2007 as my client application to format and publish CLPEX.com to the new servers.  This new application opens up new potential for site re-design, but full utilization of the Sharepoint potential will probably require more time to fully explore.  If anyone with Sharepoint experience is interested in being associate Webmaster for CLPEX.com, touch base with me at kaseywertheim@aol.com and we'll discuss the potential of new CLPEX website file collaboration potential.

Updated the Fingerprint Interest Group (FIG) page with FIG #36.

Inserted Keeping Examiners Prepared for Testimony (KEPT) #11: The Comparison Phase - is ACE a Linear or Circular Process?  Discuss this topic on CLPEX.com - a discussion has been created for KEPT.
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Last week

we looked at printer resolution for the best quality printed output.  We also looked at new R&D opportunities within the Department of Defense.

This week

we look at a the Draft for Comment from SWGFAST regarding Simultaneous Impressions.  Please note that this document is published as the Weekly Detail on CLPEX.com and by e-mail to permit wide dissemination of the information to interested parties, and that some format changes and occasional formatting errors may have occurred.  It is strongly encouraged that examiners wishing to provide comments to SWGFAST review the original version located at www.SWGFAST.org or at the following link: (http://www.swgfast.org/Simultaneous_Examination_
Standards_1.0_DRAFT_FOR_COMMENT.pdf)
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Standards for Latent Print Examinations Involving Two or More Friction Ridge Impressions as a Simultaneous Impression

Draft for Comment


Scientific Working Group on Friction Ridge Analysis, Study and Technology (SWGFAST)

Preamble

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. 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 which are consistent with simultaneity can be used in the aggregate and considered a single impression when reaching conclusions. Thus, the term is herein referred to as a simultaneous impression. The use of the term simultaneous impressions, with an “s”, infers that more than one simultaneous impression exists in a case.

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 concurrently as a single act of touch, and is referred to as a simultaneous impression (2) analyzing a simultaneous impression to determine whether it is of value for comparison purposes and how it will be compared (3) reaching conclusions from the comparison of a simultaneous impression (4) documenting the examination and (5) reporting results.

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 on an object. Specific circumstances within a case may provide an expert the opportunity to offer an opinion as to how the simultaneous impression relates to the touch or grasp of an object, which may support or refute the circumstances of touch.

The relative weight of particular evidence for legal proceedings is known as probative value with the potential of investigative insight as to how the simultaneous impression relates to the touch or grasp of an object.

Before conducting a forensic case examination of a simultaneous impression, examiners shall have completed training in the examination of latent print simultaneous impressions.
1

1. Analysis

The analysis must include (1) the determination whether the friction ridge impressions are consistent with a simultaneous impression and (2) the determination of the value for comparison of each friction ridge impression within the simultaneous impression.

The analysis will determine how the examination is to proceed in the comparison phase, for example, each friction ridge impression can stand-alone for reaching a conclusion, or the aggregate of some or all of the friction ridge impressions must be considered for reaching a conclusion. The term “stands-alone” means that a conclusion of individualization for a single impression can be reached independent of other impressions within the aggregate.

There is no scientific basis for requiring a single friction ridge impression within a simultaneous impression to stand-alone for individualization purposes [1 – 7]. This position is in harmony with the fundamental scientific principle of biological uniqueness.

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

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:

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

One or more friction ridge impressions are present on a single or multiple objects. Note: the use of multiple objects infers that the simultaneous impression may actually span across more than one object, for example, a portion of the simultaneous impression is on one sheet of paper and the remaining portion on an overlapping piece of paper (Figures 1 – 4).

Figure 1
Simultaneous impression across two surfaces (torn piece of paper).

Figure 2
Simultaneous impression with void due to substrate gap
(shape of the revolver in this image).

Figure 3
Simultaneous impression across a semiporous surface
(label) and a nonporous surface (plastic).

Figure 4
Simultaneous impression across two pieces of paper.

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.

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).

4) Substrate (surface)

Determine that the aggregate of the friction ridge impressions is consistent with the surface(s) on which it appears. Substrate examples are as follows:

A single surface such as one side of a piece of paper on which all friction ridge impressions appear.

A single surface such as the entire surface of a cylindrical or curved object on which all friction ridge impressions appear; three fingerprints on one side of a cylinder and a thumb print on the other side.

Two surfaces such as opposite sides of a piece of paper with one or more friction ridge impressions appearing on each side; a thumb print on the corner of one side and the index and middle finger on the other side.

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.

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.

5) Friction ridge skin features and anatomical features

Determine that the friction ridge skin features, for example ridge width, ridge flow, and creases, are consistent with simultaneity.

Determine that the anatomical features, for example finger height, toe span, and impression size are consistent with simultaneity.

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.

7) Distortion

Determine that the friction ridge impressions have consistent appearance related to deposition pressure, lateral pressure, and twisting. Examples, in the order listed above, are as follows:

Placing a hand on a bank counter to vault over.

Pushing up a window.

Opening a pocketknife by the blade.

Determine that the distortion(s) within the aggregate of the friction ridge impressions exhibit consistent appearance for the object and substrate.

1.2. Simultaneous impression determination

In determining whether two or more friction ridge impressions are a simultaneous impression the examiner must consider each factor listed in 1.1, individually and in the aggregate. The analysis of the applicable factors must support the determination of simultaneity. The result of this analysis will result in one of the following scenarios:

1) All friction ridge impressions are consistent with having been deposited concurrently, and, as such are considered to be a simultaneous impression.

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

3) None of the friction ridge impressions are consistent with being deposited concurrently and as such are not considered to be a simultaneous impression.

4) Simultaneity cannot be determined.

1.3. Determination of the value for comparison purposes

The simultaneous impression, as an aggregate of all friction ridge impressions, should be analyzed and will result in one of the following scenarios:

1) All friction ridge impressions are of value for comparison purposes and each stands-alone for a conclusion (Figure 5).

Figure 5
Simultaneous impression where all impressions stand-alone.

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.

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. Those friction ridge impressions which do not standalone may be compared in the aggregate in order to reach a conclusion, whereas those providing anatomical or spatial information may be used to support simultaneity (Figure 7).

Figure 7
Simultaneous impression with two impressions that stand-alone, one impression that must be compared in the aggregate, and one impression that only supports simultaneity.

4) None of the friction ridge impressions stand-alone but all are of value for comparison purposes in the aggregate for reaching a conclusion (Figure 8).

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

5) None of the friction ridge impressions stand-alone and some provide only anatomical or spatial information. Those providing anatomical or spatial information may be used to support simultaneity, whereas the remaining impressions may be used in the aggregate for reaching a conclusion (Figure 9).

Figure 9
Simultaneous Impression with two impressions that must be compared in the aggregate and one impression that only supports simultaneity.

6) The impressions may provide anatomical or spatial information and are noted solely for potential analytical value (Figure 10).

Figure 10
Simultaneous impression noted solely for potential analytical value.

1.4. Continuation of the ACE-V methodology

For each friction ridge impression determined to be of value for comparison within a simultaneous impression the examiner should proceed to the comparison phase.

Simultaneity can be supported or refuted during the comparison, evaluation, or verification phase. If it is refuted then re-analysis shall occur.

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.

2. Comparison of simultaneous impression(s)

For each friction ridge impression, stand-alone or in the aggregate, determined to be of value for comparison, the examiner should proceed to the comparison phase noting similarities or discrepancies between the impressions.

3. Evaluation of simultaneous impression(s)

For each of the scenarios provided in 1.3 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 each impression in an aggregate. Those friction ridge impressions which do not stand-alone must be compared in the aggregate in order to reach a conclusion.

Examples of evaluation conclusions are as follows:

1) All friction ridge impressions stand-alone.

2) At least one of the friction ridge impressions will stand-alone and the remaining friction ridge impressions are used in the aggregate.

3) At least one of the friction ridge impressions will stand-alone and at least one of the remaining friction ridge impressions provide only anatomical or spatial information. Those friction ridge impressions that provide only anatomical or spatial information may be used for confirmation of simultaneity.

4) None of the friction ridge impressions stand-alone but are used in the aggregate.

5) None of the friction ridge impressions stand-alone and some provide only anatomical or spatial information.

For a conclusion of individualization, the details contained within all friction ridge impressions must be in agreement across all corresponding impressions for that person.

4. Verification of simultaneous impression(s)

The analysis factors of each aggregate impression must be verified as supporting simultaneity. Each simultaneous impression resulting in individualization must be verified. Exclusions or inconclusive decisions may be verified. Any conflicts must be addressed within an agency’s conflict resolution process.

5. Documentation of simultaneous impression(s)

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

5.1. Documentation of analysis

For each applicable analysis factor listed under section 1.1, 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 written examiner notes. The information must be sufficient for another competent examiner to interpret what was done to allow replication of the analysis decision.

For each analysis factor under section 1.1, there may be either factual case information or there may be qualitative information derived during the analysis which may be necessary to document in support of simultaneity.

1) An example of factual case information is knowing the object is a bottle because the examiner personally processed it.

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.

There may be other factors than those listed under analysis section 1.1 due to the unique circumstance of touch and those factors should be documented.

For each friction ridge impression within a simultaneous impression the orientation, spatial relationship, and anatomical features shall be captured using a photograph, lift, or legible copy and annotated. Each agency performing simultaneous impression examinations shall establish a policy for consistent annotations of simultaneous impressions. The following examples are a guideline regarding annotations:

1) Distal segment of the fingerprints - Draw a horseshoe-shaped mark over the top of the distal segment of the fingerprint with one continuous line connecting all the fingerprints (Figure 11).

Figure 11

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

3) Distal, proximal, and medial segments of fingerprints and palmprint - Draw a horseshoe-shaped mark over the top of the fingerprints with 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).

Figure 13
Figure 14

4) Toeprint and footprint – Same as fingerprints and palmprints but include footprints or toeprints as notation (Figures 15 & 16).

Figure 15
Figure 16

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) stands-alone; 2) is part of an aggregate; or 3) provides only anatomical or spatial information but supports the simultaneity decision.

1) Friction ridge impressions of value for comparison that stand-alone need not be labeled as such (Figure 17).

Figure 17

2) Friction ridge impressions of value for comparison that do not stand alone but require the aggregate of all impressions will be labeled with “agg” for aggregate (Figure 18).

Figure 18

3) Friction ridge impressions of no value for comparison are indicated with a “NV” for no value, but are still considered as being of value for supporting simultaneity (Figure 19).

Figure 19

4) For each friction ridge impression deemed to be of value for comparison, the level 2 detail relied upon in reaching that determination should be documented. This may be done in writing or annotations on a photograph, lift, or legible copy. This information shall be clearly indicated as “analysis” data (Figure 20).

Figure 20
Analysis photo with level 2 detail marked in red.

5) Other impressions present on the lift or photograph which are not within the annotated simultaneous impression are marked separately and not joined to the aggregate.

5.2. Documentation of comparison

For each simultaneous impression, the case documentation must reflect all comparisons conducted with known exemplars by name or unique identifier.

A simultaneous impression compared with other simultaneous impressions (latent prints to latent prints) must also be documented.

For each friction ridge impression deemed to be of value for comparison the level 2 detail, relied upon during the comparison should be documented. This may be done in writing or annotations on a photograph, lift, or legible copy. This information shall be clearly indicated as “comparison” data (Figure 21).

Figure 21
Comparison photo with level 2 detail marked in blue.

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” indicator.

5.3. Documentation of evaluation

Each friction ridge impression of value for comparison contained within a simultaneous impression will require case documentation of the conclusion reached when compared with a known exemplar or other latent impression. The case documentation must reflect a conclusion (individualization, exclusion, or inconclusive) for each comparison conducted with known exemplars by name or unique identifier.

The conclusion of a simultaneous impression compared with other simultaneous impressions (latent prints to latent prints) must also be documented

The Standards for Conclusions2
shall be utilized. A standard for conclusion must be applied and documented for each simultaneous impression which has been compared.

The documentation must enable a reviewer to associate the comparisons conducted and conclusions rendered.

1) Individualization – Document on the photograph, lift, or legible copy the name or unique identifier of the person identified, along with the respective finger or palm designation in direct association with the marking as described in 5.1. This same information must be documented in case notes (Figure 22).

Figure 22

2) Exclusion – This information must be recorded in case notes.

3) Inconclusive – Document on the photograph, lift, or legible copy an “inc” for inconclusive for each applicable friction ridge impression within the simultaneous impression. This information must also be recorded in case notes for each individual to each latent impression (Figure 23).

Figure 23

Another example would be a scenario where four individuals were compared, no individualizations effected, and three of the four individuals were excluded but the remaining individual, due to poor quality known exemplars or for lacking the comparable area, resulted in an inconclusive comparison.

The “inc” indicator would not only be indicated on the photograph or legible copy, but also recorded in case notes and specifically associated with the name or unique identifier for that individual (Figure 24).

Figure 24

5.4. Documentation of verification

Verification documentation should be made on an unmarked photograph or legible copy and also recorded in case notes.

The case notes shall reflect the verification of simultaneity and the conclusions of the original examiner, including each individual’s known exemplars by name or unique identifier.

Any conflict between the original examiner’s decision and the decision from the verification process must be resolved3. Any conflicts must be referred to the agency’s conflict resolution process and no reporting of results should be provided until the conflict is resolved.

Blind verification shall be utilized where none of the simultaneous impressions standalone.

6. Reporting of simultaneous impression(s)

Any or all simultaneous impressions may be reported as such depending on how the impression relates to the circumstances of the touch (i.e., probative value). A photograph (digital image, photocopy) indicating the placement of the simultaneous impression on the evidence or lift may be returned with the report. The report should state: “A simultaneous impression is two or more friction ridge impressions from the same hand or foot deposited concurrently.” The following are scenarios with examples for different methods of reporting a simultaneous impression.

1) The analysis indicates the prints are a simultaneous impression and all of the friction ridge impressions contain sufficient information to stand-alone for comparison.

A simultaneous impression containing three latent fingerprints of value for comparison 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.

2) Reporting the analysis of a simultaneous impression when no comparisons have been conducted (i.e., no exemplars).

Three latent impressions of comparison value have been detected on Q1 and are consistent with being concurrently deposited.

Although the analysis indicated that these three latent fingerprints are consistent with simultaneity, it should not be inferred that these latent impressions are, in fact, placed simultaneously.

3) One or more of the impressions contains sufficient information to standalone but the remaining are insufficient to stand-alone

A simultaneous impression containing three latent fingerprints has been detected on Q1. The simultaneous impression has been individualized with JOHN DOE.

4) At least one of the prints contains sufficient information to stand-alone but one of the impressions within the aggregate only provides anatomical or spatial information.

A simultaneous impression containing three latent fingerprints has been detected on Q1. Two of the latent fingerprints have been individualized with JOHN DOE. The remaining impression within this simultaneous impression does not contain sufficient ridge detail to exclude or individualize but is sufficient to support simultaneity.

5) Reporting of analysis of a simultaneous impression when no comparisons have been conducted.

A simultaneous impression containing three latent fingerprints has been detected on Q1. Two of the latent fingerprints contained within this simultaneous impression are of value for comparison and a conclusion can be made regarding the source of the two friction ridge impressions. The two latent fingerprints are consistent with being concurrently deposited by the right index and ring fingers.

The remaining impression within this simultaneous impression does not contain sufficient ridge detail to exclude or individualize but is consistent with and has the spatial relationship to have been the right middle finger.

6) The analysis indicates the prints are consistent with being a simultaneous impression and none of the prints stand-alone, but the cumulative information is sufficient to individualize.

A simultaneous impression containing three latent fingerprints has been detected on Q1. The simultaneous impression has been individualized with JOHN DOE.

7) The analysis indicates the prints are consistent with being a simultaneous impression and none of the prints stand-alone and one of the impressions within the aggregate contains no ridge detail, but the cumulative information is sufficient to individualize.

A simultaneous impression containing three latent fingerprints has been detected on Q1. The simultaneous impression has been individualized as having been made by the right index and middle fingers of JOHN DOE. The remaining impression within this simultaneous impression does not contain sufficient ridge detail to exclude or individualize but is sufficient to support simultaneity.

8) The cumulative total of all the prints is insufficient for comparison or where the prints contain no ridge detail, but the analysis indicates the friction ridge impressions are consistent with being deposited concurrently. The impression would be reported as a simultaneous impression only for the purpose of providing insight as to the circumstances of touch.

A simultaneous impression of the right hand consisting of three fingers and a partial palm has been detected on Q1. It has been determined to be of no value for individualization but may be of value for exclusion.

7. 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) Black, J. P. Pilot Study: The Application of ACE-V to Simultaneous (Cluster) Impressions. Journal of Forensic Identification. 2006, 56 (6), 933 - 971.

3) 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).

4) Cowger, J. F. Friction Ridge Skin. CRC Press LLC: Boca Raton, FL, 1993, 154-156.

5) Ostrowski, S. Simultaneous Impressions: Revisiting the Controversy. The Weekly Detail #13.
www.clpex.com. November 5, 2001 (accessed September 2007).

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

7) 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).

[Specific Footnotes]

1 Refer to SWGFAST “Training to Competency for Latent Print Examiners.”

2 Refer to SWGFAST “Standards for Conclusions.”

3 Refer to SWGFAST “Quality Assurance Guidelines for Latent Print Examiners.”


ENTIRE DRAFT WITH IMAGES:
(http://www.swgfast.org/Simultaneous_Examination_Standards_1.0_DRAFT_FOR_COMMENT.pdf)
http://www.swgfast.org/Simultaneous_Examination_Standards_1.0_DRAFT_FOR_COMMENT.pdf


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KEPT - Keeping Examiners Prepared for Testimony - #11
Comparison phase - is ACE a linear or circular process?
by Michele Triplett, King County Sheriff's Office

Disclaimer:  The intent of this is to provide thought provoking discussion.  No claims of accuracy exist. 

 

Question - Comparison Phase - Is ACE a linear or circular process?

When you did your comparison did you go back and forth between the latent and the known print?

 

Possible Answers:

a)      No, because that would create circular reasoning.

b)      No, because if you do this then you’re at risk for making the latent print fit the known print.

c)      Yes, I move back and forth between the latent and the known.

d)     Yes, I move back and forth between the latent and the known print, confirming the characteristics between the images are the same.

 

Discussion:

This question is implying that bias is created if you don’t do a full analysis of the latent print prior to moving to the comparison phase.  The key factors in arriving at a conclusion of individualization are consistency between the two prints and a sufficient amount of information to arrive at that conclusion.  ‘When’ someone noticed a characteristic was consistent isn’t a factor in establishing if that characteristic can or should be used.  The decision to use a characteristic should be based on the reproducibility of that feature and any visual distortional information that may go along with that characteristic.

Answer a:  Going back and forth is a circular process which is different than circular reasoning. 

Answer b:  Going back and forth may increase the tendency to make the latent fit the known print and as experts we need to understand this phenomenon and account for it.  Scientific methods allow us to use a circular process as long as we understand the shortcomings and protect against them when it’s needed (perhaps with blind verification or peer review).

Answer c:  Some books and articles promote using ACE as a linear process to prevent bias from being introduced into the comparison process.  This will diminish bias but too much valuable information can be lost by using ACE in a linear fashion.  Science promotes using a circular process by encouraging re-evaluating your own work as well as re-evaluation of the work of others.  Science also promotes going back to the beginning of any experiment and collecting more information to test your conclusion.  Science accounts for any bias that could be introduced by using other quality assurance measures.

Answer d:  This answer is the same as c with the additional ‘confirmation’ statement added.  This word should be avoided because scientific methods discourage confirmation and promote trying to falsify what we think is true.  Trying to falsify our beliefs will insure we aren’t drawn into biasing factors and insures we aren’t trying to make the images match.

 


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