In this day of cutting edge forensic techniques highlighted in T.V. shows like CSI, Law and Order, and NCIS the human imagination seems to be the only limit on what investigators are capable of. In preparation for a recent Duplin County felony case I had to do a bit of research that made evident to me just how far fetched some of these shows are, and how some of the oldest and most basic forensic techniques aren’t as foolproof as most of us believe. Prior to my research, fingerprint evidence, in my mind, was a tried and true investigative technique that investigators as far back as Sherlock Holmes have used to crack cases.
The case I was dealing with had a very simple fact pattern. In the early morning hours the victim in the case heard a noise coming from the toolshed in his back yard. He turned on the exterior lights in time to see two males attempting to make off with his grandson’s motorcycle. They dropped the motorcycle and took off running. When investigators arrived they found the motorcycle lying on the ground, and a set of bolt cutters on the ground nearby. No suspects were found and the victim was unable to identify the would be cat burglars. Investigators were able to lift 8 prints from the bolt cutters. Two of the 8 prints proved “clear” enough to compare and were considered a match to my client. He was arrested and charged with the attempted theft.
Knowing that the fingerprints were the only thing that linked my client to the scene (in spite of the victim emphatically saying that my client’s build did not match the build of the men he saw fleeing), it became imperative to poke holes in the fingerprint evidence.
On November 22, 2005, the Science, State, Justice, Commerce, and Related Agencies Appropriations Act of 2006 became Federal law. Under the terms of the statute, Congress authorized the National Academy of Sciences to conduct a study on forensic science. The committee selected to conduct the study included members of the forensic science community, members of the legal community, and a diverse group of scientists. The results were published in 2009 under the title “Strengthening Forensic Science in the United States: A Path Forward”.
The committee conducted extensive studies in the field of latent fingerprint evidence and in particular the ACE-V method of examining and comparing fingerprints. The study concluded by saying “’We have reviewed available scientific evidence of the validity of the ACE-V method and found none.’” Id. at 5-12 (emphasis added). See the section on latent evidence here. In particular the study concluded that “ACE-V does not guard against bias; is too broad to ensure repeatability and transparency; and does not guarantee that two analysts following it will obtain the same results.” 2009 NAS Report at 5-12.
The argument is an interesting one. In essence what the committee concluded is that the ACE-V method of fingerprint analysis is subjective to the point that it can’t be relied upon in a legal context. The ACE-V method doesn’t set forth particular sections or features of a fingerprint to analyze in every case because each analysis is different. Using the ACE-V method, two analysts might reach two entirely different conclusions. In fact, it’s not inconceivable for the same analyst to come up with two different conclusions on the same set of prints.
My case concluded before we could ever litigate the fingerprint issue. I was unable to find any examples of trial courts excluding fingerprint evidence based on the 2009 NAS study. I don’t know if a judge would exclude fingerprint evidence based on the study or not because of the reliable reputation that fingerprint evidence has enjoyed for so long. However, if a judge were to honestly analyze the results of the the NAS study in light of our rules of evidence it would be difficult to fashion a valid reason to not exclude the evidence.