BCA Forensic Scientist Gives Inside Look At Firearm Comparison Tests
MINNEAPOLIS (WCCO) -- Forensic experts are working to determine if the shotgun found in Jake Patterson's Gordon, Wisconsin, home was the one used to fatally shoot Jayme Closs' parents.
The Bureau of Criminal Apprehension has a lab where they test firearms.
Though the BCA is not involved in the investigation in Wisconsin, they gave Reg Chapman an inside look at how firearm comparisons are completed.
It all begins with the test firing of a weapon taken from a crime scene. A shotgun is fired into a lead backstop, giving forensic scientists ammunition components or shell casings to compare.
"We'll put our test specimens against one another to make sure we are getting reproducible markings from that firearm and on our ammunition. Then we'll compare our test specimen shotshell in this case to a shotshell that was recovered at a scene," Travis Melland said.
Melland, a BCA forensic scientist, says a comparison microscope is used to figure out the rest.
"This one is our test specimen on the left, this would be our evidence specimen on the right and then we look at a lot of these fine striations which occurred during the firing of the firearm," Melland said.
Melland says the microscope reveals the shotgun's fingerprints. If there is no match, information is entered into the National Integrated Ballistic Information Network.
"We can enter it into this database and it will compare to all other shotshells or cases of that similar caliber or bore or gage and compare it," Melland said.
If there is a weapon recovered and it's damaged, it's off to the weapons library where more than 6,000 weapons are stored.
"We can then come into our reference collection, hopefully find the same make and model and swap out different parts to make that firearm functional again so then we can make test specimens from that," Melland said.
Travis says this forensic testing is very tedious.
"It can be days to weeks," Melland said.
