More problems with fingerprints
I'm one of the newest members of the American Academy of Forensic Sciences, and was anxiously waiting for my first journal. It arrived several weeks ago - in 2 volumes - and I started looking at the articles. Most are highly technical - but there are a few that deal with criminal justice issues. I'll cover other topics in subsequent posts, but thought I would start with an article on fingerprints.
The title is "Emotional Experiences and Motivating Factors Associated with Fingerprint Analysis", and was written by David Charlton, Peter A.F. Fraser-Mackenzie and Itiel E. Dror. They conducted a study to determine what impact emotional factors had on the typical day to day work of a fingerprint examiner. Despite what many believe, fingerprint analysis is not as objective - and cut and dried - as many people think. Other studies have shown that the same fingerprint examiner may not reach the same conclusion - depending on the background information provided. So what did they find out?
What is certain as a result of this study is that fingerprint examiners not only are emotionally driven and motivated to achieve results for themselves, their employees, police and wider society, but also are influenced by more subtle psychological factors such as need for closure that exert leverage upon the decision-making thresholds of examiners that may, in the right circumstances, lead to erroneous conclusions should the context and the motivation be strong enough.
So what does that mean? One thing they discovered was the need to close a case - which is strongest in high profile and serious cases - may result in the decision threshold being lowered. In other words, they are more likely to call a match. As you would guess, the examiners wouldn't be aware of such influences, and would probably feel they had been objective and reached the correct result.
This article is yet another attack on the sacred position of fingerprints. They are not the error proof - definitive evidence - that fingerprint examiners have always tried to convey. In other words, fingerprint examiners can be wrong. By identifying the potential for mistakes, not only can bad identifications be challenged, procedures can be put in place to limit mistakes in the future.
