How accurate are fingerprints?
The use of fingerprints has been around for a number of years. If you have ever been in a court room, you've heard the statement that no two people have the same fingerprint. While that sounds convincing, there is no evidence or research to back it up. For the most part, fingerprint evidence has avoided scientific scrutiny. Instead, it has been accepted by all those involved, including defense lawyers, as accurate.
The reliability of fingerprints is questioned in the recent report by the national research Council, on strengthening scientific evidence. In their report, the Council examines friction Ridge analysis, which covers fingerprints, palm prints, and soul prints. The report contains several startling statements.
Before going further, the terminology used must be understood. The technique used to examine prints is described by the acronym a ECE -- the, which stands for analysis, comparison, evaluation, and verification. The Council notes that this mess did does not specify particular measurements or standard test protocol, and the examiners must make subjective assessments there out. The Council notes that the standards are deliberately kept subjective. We'll they also note that the outcome of friction Ridge analysis is not necessarily repeatable from examiner to the examiner, and cited research which shows that experienced examiners do not even agree with their own past conclusions when presented in a different context.
Over the last several years, some of the problems with fingerprint comparison have been discussed. The problem is not with comparing a set of ink fingerprints. Instead, the problem is in comparing prints left on a surface. As the Council notes, a small stretching of distance between two fingerprint features, or a twisting of angles, can result from either a difference between the fingers that left the prints are from distortions from the impression process, which means analysis must rely on subjective judgments. In other words, an examiner must not only determine what he is looking at, but how relevant the impression is.
In its summary, the Council concludes that the current methods do not guard against bias, are too broad to ensure repeatability and transparency, and do not guarantee that two analysts following it will obtain the same results. For that reason, merely following the steps of the excepted method does not mean an examiner is proceeding in a scientific manner, or producing reliable results. The Council also notes that it has reviewed the available scientific evidence on the validity of the process, and has found none. And a minimum, the Council notes that absolute opinions are not appropriate in this area.
The report is must reading for anyone who has a fingerprint case. We cannot accept the opinion or conclusion that a print belongs to our client. As with many disciplines, the problem will be finding someone who can explain the process. I suggest that will not be another fingerprint examiner, who will operate under the same old assumptions. This is not an exact science, and never should have been considered as such. Hopefully, courts will become more sensitive to the problems. It's our job to make sure that happens.
Do you have a link to the report?