we turn to the concept of identification conclusions, and review an article by Dusty Clark.
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Conclusions That Can Be Drawn from the Detail Present
by Dusty Clark
www.latent-prints.com
Article: http://www.latent-prints.com/id_criteria.htm
Pub Date: 5/16/03, Download Date: 7/31/01

As there are no clear standards of sufficiency for individualization, every ridge present is potentially capable of being individualized based upon the ability of the analyst and their own criteria to reach a definable individualization threshold.

The Individualization standard of minimum sufficiency is based upon some sort of standard (agency or individual) to retain the evidence when it is first observed. Many agencies have a numerical threshold or a clarity threshold standard for the crime scene analysts to determine whether or not to recover the latent impression at the crime scene or from evidence. An impression has value as long as any conclusion can be reached. Only when no conclusion can be reached is an impression of no value.

A single ridge characteristic that could be from any area of friction skin without any focal point for location orientation would be of little value to reach any conclusion. That same single ridge characteristic whose location in relationship to a definable source area (recurve / triradia etc.) can be determined has value as a conclusion can be reached.

Impression evidence is circumstantial. Determination of circumstantial evidence sufficiency is the function of a judge or jury. An impartial reporting of exclusion or inability to exclude should be an analyst's conclusion, based upon scientific criteria. If an impression can exclude a possible source, then scientifically it must be able to include. Reporting of only one possible conclusion (exclusion) based upon fingerprint practitioner's social and regimented practices is not scientific.

A fragmentary impression so crucially linked to the commission of the offense, which does not have value to individualize, is often reported as having no identification value. If a named suspect shares information less than sufficient to individualize with this latent impression, and the information between the known and unknown is similar in all aspects and dissimilar in none, most analysts will call the impression no value. If a subsequent suspect is arrested and this same latent is dissimilar in all aspects, the difference will not be reported as it is already of no value. It may be of no value to individualize, but it has sufficient value where a conclusion can be reached.

AN EXAMPLE

I shoot you with a .22 cal weapon and the recovered slug from your autopsy has no striations for individualization. The fingerprint argument against inclusion would be no different than the jury cannot be told that I own a .22 cal rifle and the rifling and twist agree with it.

The same argument with a bloody fingerprint on the murder weapon. The only detail present is 4 ridges. A recurve with three ending rods above the shoulders of the recurve. No complete pattern is visible. The clarity of ridge detail is just minimally levels 1 and 2.

1. The entire hand and foot prints are available where all recurves are recorded.

A. The level 1 and 2 do not agree with the arrested subject, John Jones.

B. The level 1 and 2 agree with suspected subject John Doe.

2. In this scenario do you:

A. Report the impression as no value?

B. Report the impression as exclusion to John Jones and report no value for individualization to John Doe?

C. Report the exclusion to John Jones and the inability to exclude John Doe?

It is not the fingerprint examiners responsibility to only convict. It is the duty of the analyst to also report exculpatory information. Regulatory sanctions such as IAI resolution V should not be so restrictive as to limit the free reporting of accurate scientific conclusions. Inclusion (unable to exclude) is a scientific conclusion. The degree of probability will never be greater than 50% as there are only two possible equal conclusions. Until the individualization threshold is reached, the total amount of agreement is irrelevant. The same probability of 50% exists with a smudged no value impression, however absence of evidence is not evidence of absence. The presence or absence of ridge features consistent between the unknown and the known impressions gives measurable definitive data to reach an absolute conclusion.

FRICTION RIDGE IMPRESSION VALUES

CONCLUSIONS THAT CAN BE DRAWN FROM THE DETAIL PRESENT

I-C-E-I-N

I-DENTIFICATION VALUE

The latent impression contains a sufficient amount of clear ridge detail to effect an opinion of individualization

C-OMPARISON VALUE

1. The impression contains ridge events that lack clarity and are subject to interpretation. Inked impressions are needed for comparison to determine if concurrence exists.

2. The impression lacks a sufficient amount of ridge detail to effect an identification.

3. The possible source area of the impression may be determined. A comparison may result in the opinion of exclusion or inclusion.

E-XCLUSION VALUE

1. The latent impression lacks sufficient ridge detail for identification.

2. The presence in the latent impression of a pattern, or ridge detail from a definable source area.

3. A comparison of inked impressions would result in an opinion of exclusion if the latent impression ridge detail did not concur with the inked impressions.

I-NCLUSION VALUE

1. The latent impression lacks sufficient ridge detail for identification.

2. The presence in the latent impression of a pattern, or ridge detail from a definable source area.

3. A comparison of inked impressions would result in an opinion of inclusion if the latent impression ridge detail concurs with the inked impressions.

N-O VALUE

The latent impression lacks sufficient ridge detail for comparison or identification purposes.

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