CLPEX Chat Board

Hello all,
I wondered if anyone had information on studies/ results on the percentage of times latent fingerprints were actually left on evidence (specifically weapons).
An officer preparing for testimony in an upcoming case was asked if he had any information on this subject by a D.A.
Any information on this matter would be helpful

Clive Barnum and Darrell Klasey with the ATF lab in San Francisco did some research into latent print recovery statistics from weapons and published it in the JFI 12 or 15 years ago. I'm out of town right now without access to my old JFI's, but if memory serves me, they calculated about 10% ident rate on weapons cases. They attributed the lack of latent prints on weapons to the fact that most weapon finishes are designed to repel moisture.

Macgyver 130.

I have Barnum and Klasey article in word and PDF.

If you want a copy e-mail me and I will forward you a copy. My e-mail is listed on this site.

Very good article---should be in every library.

Thanks Guys.
I knew there had to be something out there. My co-worker and I were discussing this topic and agreed the percentage had to be low...just based off of the processing we have performed ourselfs with firearms.
Charles, I'll give you a shout and get that information from you. I would like to see the details and it will give me something solid to tell the officer asking about it.

For the raw data on the Barnum and Klasey article:

Study was done from Feb. 1992 to Aug. 1995.

1,000 firearms processed.

recovered 114 identifiable** latent prints from 93 firearms

24 latent prints identified to suspects

1 latent print identified to other

Note: They mentioned that palm prints were not usually submitted and so no comparisons were made with latent prints consistent with palm prints.

**Identifiable not Comparable----Big Difference.

I would like to see this study done again. Any Takers.

I just did a study on the percentage of time we get usable latent prints from residential, vehicle, and commercial burglaries as well as robberies and carjackings. Should have results published soon. Our statistics show that we obtain usable latent prints approx. 28% of the time on residential and commercial burglaries, and over 40% from vehicles.

There are other factors affecting the final results (i.e. officers at scene pre screening calls, etc.). All of our forensics are trained to recognize a latent print of “value”.