Firearms and toolmark identification explored

MSP sergeant discusses career in forensic science

By  Roberta M. Gubbins
Legal News

“I tell the story that the evidence tells me, “ said Sgt. Jeff Amley of the Michigan State Police (MSP) Firearm and Tool mark Unit, speaking to the Ingham County Bar Association Criminal Law Section.

“A lot of what I do does not put the gun in the suspect’s hand,” said Amley. However, using his skills he can eliminate or identify a bullet found at the crime scene.

 The meeting took place at Thomas M. Cooley Law School on March 22.

“Firearms and tool mark identification,” he said “is a forensic science that attempts to identify a particular fired bullet to a specific firearm. It also encompasses tools. I attempt to identify or eliminate pry bars, bolt cutters, knives to tires, cut hoses, etc.”

Amley conducts tests to answer some of the questions presented by the crime scene.

The range of tests available to Amley include:

• Open shoot/Firearm Function Test/IBIS: Firearm exam/function test, open shooting file comparison and submit test shots for Integrated Ballistic Identification System entry.

• Serial Number Restoration (SNR): Restoration of firearm serial numbers or VIN numbers that have been ground off, scratched, drilled, peened, etc. utilizing polishing, chemical, and magnetic means.

• Fired Cartridge Case/Fired Shotshell Comparison: Compare with submitted firearm or additional fired cartridge cases/shotshells if not suspected firearm submitted to determine if more than one firearm involved, with evidence retained in open shooting file, and IBIS entry.

• Fired Bullet Classification and Comparison: Determine caliber and class rifling characteristics to identify possible firearms involved, determine type of ammunition, ID or eliminate multiple fired bullets as having been fired from the same firearm barrel or determine more than one firearm involved, and compare with open shooting evidence.

• Fired Shotshell Classification:  Determine possible manufacturers from recovered evidence components (wad, shotcup, shot type, rifled slug, shot size, etc.)

• Muzzle to Garment Distance Determination:  Determine muzzle to garment range using the suspect firearm and suspect ammunition used in the incident, the victim’s clothing, Witness statement(s) (if any), and information on intermediate barriers if any (object shot thru prior to striking victim such as a curtain, pillow, bag, etc.). We do not process GSR hand kits.

• Malfunctioning Firearm Exam:  Many of these cases (such as accidental discharges) will deal with the question: “Will the firearm fire without pulling the trigger?” In these instances we need a detailed account of the incident in an attempt to confirm or refute what was reported.

• Classification and Examination: ID or eliminate suspected tool with submitted evidence or evidence mikrosil casts. Suspected tool has to be linked to a suspect.

• Shooting Incident Reconstruction: Determine a probable sequence of events that occurred during a shooting incident based on trajectory analysis, recovered evidence, photographic evidence, scene sketches, ejection pattern analysis, officer and witness statements, etc.

Some of what people see on television is true, Amley noted, but what is not true is the speed of the Integrated Ballistic Identification System (IBIS). 

In CSI and its like, the bullet from the murder scene is put into the system and the results of the query come back “in a matter of minutes. In reality, that does not happen. Some of our examinations can take a couple of hours while others take months.”

Amley began his career as a trooper eventually moving on to become a crime scene technician and entered the Firearm and Unit in 2004.

“I went through the apprenticeship program where I completed two years of training, which is required by our discipline.”

Amley has completed many research projects and is now considered an expert, frequently testifying in court.

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