Fingerprint evidence has been admitted into the courtroom for over 100 years; therefore courts are highly unlikely to start limiting the admission of fingerprint testimony.
In an ideal case, an examiner will receive a clear and well preserved fingerprint from the crime scene – or better yet, several prints left by the same person – and be able to easily compare them to the suspect’s fingerprints.
However examiners are rarely lucky enough to enjoy such a smooth process. The print is much more likely to be smudged, missing a significant portion of the detail, depict only a small portion of the finger, or be found on a surface that makes preservation difficult.
In competent hands fingerprint examinations are valid, and they can yield correct results, consistently and reliably. (To learn more about validity, view the video Correct, Consistent, Competent on the right side of this page.) It is improtant to distinguish 10 to 10 card comparisons (which are considered more accurate) and analyses of a single, partial, distorted print. Legal professionals simply need to be aware of the limitations inherent in these procedures, so they can realistically assess the admissibility of the examinations.
Fingerprint comparison has enjoyed a long and largely successful history, and there is considerable support for the reliability of fingerprint comparisons in a majority of cases. Whether fingerprint individuality has a scientific basis has been questioned, and there have been some cases and some studies that clearly show that fingerprint comparison is not infallible. The courts however, have been very reluctant to find fingerprint (and other pattern) comparison inadmissible because of the support for its reliability and its lengthy track record.
The existence and speed of AFIS systems also makes it possible to obtain validations and research that was before unimaginable. Through these systems, finger print patterns can easily and quickly be compared with hundreds of thousands of others to look for similarities and differences. AFIS does not produce matches. Rather, it produces a list of candidates which the examiner must then compare to the crime scene. Many examiners do not even want to know what the AFIS score or ranking is.
This increasing sharing of data and ongoing improvement of technologies is an example of how additional funding for forensic sciences can continue to improve the reliability of evidence.