Like all Latent Print Examiners employed by the Division of Criminal Investigation I frequently receive evidence submitted which is to be examined for the presence of latent fingerprints. Quite often the request asks that we search any developed prints using the Iowa A.F.I.S. (Automated Fingerprint Identification System). This is a logical request, and a wise use of available resources. We occasionally find that the requesting agency (often members of our own D.C.I.) had a suspect in mind with a prior record and fingerprints on file in the D.C.I. Bureau of Identification. Unfortunately, the requesting investigator often is under the assumption that if a print is searched with A.F.I.S., it carries the same degree of certainty as if the latent was searched against the suspect’s known prints. Unfortunately, this is not the case!
For many reasons, a latent fingerprint searched against the A.F.I.S. database may not have the correct corresponding inked fingerprint in the list of possible matches, (respondents), which is generated by the system. One of the many causes for missed A.F.I.S. identifications is that the plotted minutia on the latent to be searched was improperly entered. Without being too technical, the ridge characteristics which we refer to as end ridges and bifurcations are recorded as to their location and direction of flow of the ridge or ridges. There are a maximum of 150 minutia recorded on the thumbs, index, and middle fingers, with the ring and little fingers having a 100 and 80 maximum, respectively. The polygonal arrangement of these recorded characteristics is called minutia plot. If these characteristics are not recorded or plotted accurately, it will be nearly impossible to have success in the subsequent search. Fingerprint Technicians in the Bureau of Identification at the D.C.I. are careful in seeing to it that characteristics are properly recorded. The Technicians also compare subsequent arrest fingerprint cards against fingerprints of the arrestee currently in the database. If better fingerprints are found on newer cards, the print(s) are edited in, which enables the best possible print to be available for search.
Many problems seemed to originate with the initial entering or “scanning” of the fingerprint cards which was done in 1988. In order that the system could be up and running as quickly as possible, fingerprints to be entered at the time were sent to Anaheim, CA, for entry into the original database. As expected, this was a “quick and dirty” operation and not as much care was taken in entering the prints as we might have desired. During a recent homicide of an unknown victim, one known print, (deemed as being of “search” quality), was recovered from the victim’s burned and decomposed hands. I searched the fingerprint several times on A.F.I.S., with no results. After the victim was finally identified, (as result of an A.F.I.S. hit from another state), I examined the minutia plot of the fingerprint which I had searched on the Iowa A.F.I.S. database. I discovered that there were very few of the 150 minutia points properly plotted. There is no way of telling how many other improperly recorded fingerprints exist in the system. An effort will be made to get the prints “cleaned up”, but it will take a considerable amount of time and effort. In the meantime, these improperly plotted fingerprints will continue to be missed when an A.F.I.S. search is conducted.
There are other reasons for missed A.F.I.S. searches, including:
- Smudge(s) on the ten print card result of processing at the time of the arrest.
- Carelessness when entering minutia on the print to be searched.
- Improper print orientation (misinterpreting the print’s 12 o’clock position)
- Misinterpreting a partial palmprint as a fingerprint.
This beings me to the title of this paper. When a latent prints is developed on a submitted case, the Latent Print Examiners at the D.C.I. need numbers, including the D.C.I. arrest number if applicable, as well as a birthdate and/or social security number is available. If supplied with these numbers, Examiners can obtain a set of known ten-prints when applicable, and conduct a manual search of the latent. As stated previously, A.F.I.S. may in fact not include the matched print in the list of respondents, but a trained examiner won’t.
I have mentioned that palmprints have been searched in A.F.I.S. We have found that nearly one-third of the latent prints which we develop are palmprints. For that reason, it is necessary to submit known inked palmprints, (if available), in order that we may complete the examination. The D.C.I. encourages agencies to obtain known palmprints in addition to the ten-print cards at the time of arrest, particularly since chapter 690.2 of the Code of Iowa allows it.
In conclusion, a special thank you is due to the agencies continuing to improve the quality of evidence submitted to the Latent Fingerprint Section of the D.C.I. As usual, you are always welcomed to call us with comments and suggestions.
John Kilgore; Criminalist
D.C.I. Crime Lab – Wallace State Office Building
Des Moines, IA 50319
(515) 281-3666 FAX (515) 242-6297