New fingerprint study may serve as guide to challenging forensic evidence

Criminal defense attorneys can thank the federal government for publishing a free guide on how to challenge fingerprint examiners on cross examination.

Just last week, the Expert Working Group on Human Factors in Latent Print Analysis published their final report. Despite bearing the dense title of Latent Print Examination and Human Factors: Improving the Practice through a Systems Approach, this publication is a guide to all of the human errors that can compromise the fingerprint comparison and examination process.

A long read at 248 pages, the report is practically a "how-to" guide for the cross examination of a latent print examiner. For instance, many print examiners still testify that, when they make an identification, they are do so to the "exclusion of all others in the world." Neither science nor statistics support such a statement and the report calls on examiners to stop making these unsupported claims.

Many other topics are covered including the proper preparation of a report, ethics for examiners, and the importance of being equally accessible to both prosecution and defense to answer questions before trial.

Since the release in 2009 of the National Academy of the Science's landmark critique of forensic sciences in the United States, the reports and recommendations of various Scientific Working Group have become required reading for any defense attorney preparing the cross examination of a forensic expert.

This recent report, along with the best practices for examiners recommended by SWGFAST, and The Fingerprint Sourcebook, collectively represent the best practices for fingerprint identification and should be part of any criminal defense attorney's library.