Fingerprints

The National Institute of Justice has now put The Fingerprint Sourcebook, by the Scientific Working Group on Friction Ridge Analysis, Study and Technology (SWGFAST), et al., March 2011, Chapters 1, 4 – 8, 10 – 13, and 14 – 15 on line. It appears that the remaining chapters will be published “in stages.”

I was particularly interested in Chapter 15: Special Abilities and Vulnerabilities in Forensic Expertise (pdf, 24 pages), By Tom Busey and Itiel Dror, which concludes:

In a post-Daubert environment, there is a need for additional research in the field of friction ridge science. Certainly any science wishes to expand the depth and breadth of knowledge of the discipline. We in the fingerprint expert community must attempt to challenge and study further the laws and theories that comprise our discipline. Specifically, we must focus our efforts to reevaluate the basic tenets of individualizing friction ridges using modern and enhanced technologies, which were not available in Galton’s day. There are many unanswered or partially answered questions regarding the individuality of friction ridge skin and the forensic comparison of friction ridge impressions. Although significant advances have been made, many of them in just the last two decades, this is really only the tip of the iceberg. With the advent of newer, more powerful technologies, software, and computer algorithms, we have opportunities to explore our vast fingerprint databases and quickly growing palmprint databases. We need to assess and quantify the full extent of variation of friction ridge features, starting with perhaps the most basic (patterns and minutiae—if one can truly call this “basic”) and then attempt to assess and quantify other features such as creases, scars, edge shapes, and so forth. It should be clear that there are aspects of this discipline that have been well-established and well-studied (particularly the biological theory of friction ridge formation and persistency). However, it should also be clear that there are areas of study that are woefully lacking (e.g., distortion, tolerance). The absence of available published research into some aspects of the discipline speaks volumes toward what our mission should be.

One acknowledgement is that the result in a fingerprint comparison may only be as good as the examiner. That reminds of Hastis at the Brooks Air Force Lab, or the testers at Brooks who were themselves doing drugs (tough to read charts when your high), or Mills at USACIL, and the more recent incident of the examiner at DCFL. This would be a reason why it is so important to have discovery of personnel issues and reliability of those conducting forensic examinations.