Jamie Zaleta, a VCU Forensic Science graduate student, holds a bullet casing in the VCU Police Department's firing range in November 2021. Credit: Corey Byers, University Public Affairs
Typically, officers are the only ones using the firing range in the basement of the Virginia Commonwealth University Police Department’s headquarters.
However, when VCU Department of Forensic Science graduate student Jamie Zaleta needed cartridge casings for her thesis project, the room became both a firing range and a classroom.
Zaleta was interested in undertaking research on fingerprint development, specifically latent prints on different surfaces. To complete the initial phase of her project, Zaleta needed 500 fired cartridge casings—250 brass and 250 nickel plated.
During the summer and fall semesters of 2021, Zaleta visited with VCU Police Sgt. David Nigro, a firearms instructor. Nigro would hold each unfired cartridge before loading it into the firearm, then fire them so they could be collected.
“For consistency, the same person’s fingerprints must be used during the loading process and the same firearm must be used,” Nigro said.
For Zaleta, it was valuable to have someone at VCU Police to assist with generating the fired casings.
“I know we had a few options, go to a shooting range and do the shooting ourselves, [but] then we would have had to pay fees for a range. It was definitely helpful to have a place to go and have someone who is very familiar with firearms.”
After Nigro fired each cartridge, Zaleta, who wore gloves, carefully collected the casings from the ground to catalog them for examination. She then tested two techniques to see which would yield a clearer fingerprint.
“With MBD dye staining…you submerge the fingerprint in [dye] and it will adhere to the surface of the fingerprint,” Zaleta said. “The other method is gun bluing; gun blue solution corrodes metals and [causes] them to turn black, but when there's a fingerprint present, it protects the metal and makes the fingerprint stand out.”
Zaleta wanted to see how different methods for pulling prints could be applied to the surface of a bullet casing.
“My research just focused on cartridge cases because those are a more difficult surface,” she said. “MBD in particular is a very well-established technique for other surfaces; gun bluing is used for metals because of its corrosive effect.”
Zaleta said the MBD dyeing was “a bit more successful” in revealing prints compared to the gun bluing.
“Because of the firing process, fingerprints on cartridge cases aren’t great,” she said. “Even high-level techniques don’t necessarily work super well in getting super valuable fingerprints.”
In spring 2022, Zaleta successfully defended her thesis for the physical evidence track of the forensic science master's program and earned her master’s degree.
“It’s definitely a valuable project in the field... of course this is only one project in a million that could be done in this area, but it’s definitely good for forensic laboratories to be aware,” Zaleta said. “To be able to contribute to that body of knowledge is especially valuable.”
Republished courtesy of VCU.