Does anyone know of any good links or articles that are detailed on the proceedures of some of the new techniques being tried to developed prints on firearms and casings. I am especailly interested in the use of method using an electric charge and toner or the gun bluing methods.
Well Steve, Thank You. I was pleasantly
surprised with the effort you have put forth toward my question. One of the
reasons I want this info is that besides keeping up with current and new
methods to increase success rates, myself and my co-workers will have an opportunity
to use a large number of old firearms to test different methods before my
agency sends them out for destruction. Plus it would be great to start
testifying to success rather than giving negative testimony in court.
I have posted the article from the IAI Journal: Enhancement of Latent Prints on Metal Surfaces, Karie Smith and Chris Kauffman, Journal of Forensic Identification, 51:1 (2001) which discusses the use of 'Brass Black' and 'Aluminum Black' over 'Gun Blue' solutions.
There's nothing wrong with giving negative testimony. The most important thing is that you understand and can appropriately educate the jury as to why you were unsuccessful in developing latents on firearms.
Latent Print Recovery on firearms has been studied and shown to be successful in only about 10% of the cases. The results of that study are published and can be found here: http://www.scafo.org/library/130303.html
Considering the facts cited in the study the most control you have in increasing the success rate would be to ensure your collection of the firearm doesn't involve touching it in the normally handled areas and superglue fuming the item prior to packaging it for processing at the lab. All the other factors are out of your control.
A news article is still up on fingerprints being taken from firearms even after they have been wiped off, could you help me understand that, and I would love to get a good hand held UV light for X-mas, any ideas, by the way Great site it has greatly helped me for my college search and learning about the field. Is there any way to find previously posted articles?
New process for fingerprints from firearms: it appears that the researchers used electrostatic charges with a toner to find prints on metal surfaces that were etched in by the salt left behind from fingerprints (salt is one of the four things that make up fingerprints-moisture, oils, amino acids, and salt). It sounds a lot like the ESDA process for detecting indented writing on paper. ESDA uses an electrostatic charge and toner to reveal indented writing (see: http://www.fosterfreeman.com/products/documents/esdalite/esdalite.html ). However, I have no idea about the science behind the new fingerprint process because I have only seen the newspaper story about it: http://www.hindu.com/thehindu/holnus/008200811021131.htm
As far as a good hand held UV light: I use a forensic light from Xenopus Electronix: http://www.xenopuselectronix.com/xeled/indexcsi.html
They have some light sources that are affordable. The one I use is a good all-around crime scene forensic light and is the XeLED-Cr7BL-R2-465-K. It sells for $395 on their website. They have another one for the same price that also has the UV range and is the XeLED-Cr7UV-R2-CSE.
If you are refering to the technique developed in Britian that developed prints on fired casings. You can actually e-mail the people in the article and they will respond. I asked about the technique and what they used (ie. would an electrostatic dust lifter provide enough charge to the casing). They did not think this would work since a (-) 2000V charge needed to be applied. They did advise on what equipement they used and modified to do the process (the base part cost $2000, the powder they use was something document examiners used). Due to the cost we/I have not gone any further. But they are more than happy to process any cases you wish to send them.