Draft Standard for Friction Ridge Examination Conclusions Now Available
The OSAC Friction Ridge Subcommittee recently released their draft standard for friction ridge examination conclusions to the AAFS Academy Standards Board (ASB) to continue through the standards development process. This document provides substantial improvements to the SWGFAST recommendations and positions the friction ridge community to be on stronger foundations as it relates to the expression of source conclusions. Key highlights include:
- Expansion from three categorical conclusions to a five conclusion scale.
- Source Exclusion
- Support for different sources
- Inconclusive/Lacking Support
- Support for same source
- Source Identification
- Revision to the definition of source identification – expressed as a “strength of evidence” statement as opposed to implying an individual is the source to the exclusion of all others. The revised definition is:
- Source identification is 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.
- Explicit guidance regarding qualifications and limitations to the expression of source conclusions:
- 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.
- An examiner shall not suggest that the offered conclusion is an expression of absolute certainty.
- An examiner shall not assert or imply that latent print examination is infallible or has a zero error rate.
- An examiner shall not cite the number of latent print comparisons performed in his or her career as a measure for the accuracy of a conclusion offered in the case at hand.
- An examiner shall not use the expression ‘reasonable degree of scientific certainty’ or similar assertions as a description of the confidence held in his or her conclusion.
The complete draft standard is available on the webpage.