Expert Firearms Examiner Explains Forensic Ballistics & Firearm Identification

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Summary

Harry Jey, supervisor at the Vermont Forensic Laboratory, testifies as an expert in firearm and tool mark examinations. He details his background, the process of forensic firearm identification, and the comparison of evidence in a specific case involving a Glock 19 pistol.

Highlights

Discovery of Fabric on Bullet
00:38:39

During the examination of bullet 84A, Mr. Jey discovered and removed a piece of fabric (State's 84b) lodged in its nose cavity, which was then returned to the Vermont State Police.

Introduction of Expert Witness
00:00:23

Harry Jey, supervisor of the physical comparison unit at the Vermont Forensic Laboratory and a qualified firearm and tool mark examiner, introduces himself and details his 20 years of experience in the field, including thousands of comparisons and over 40 court testimonies in Vermont. He is qualified as a subject matter expert in firearm and tool mark examination.

Forensic Firearms Identification Process
00:05:12

Mr. Jey explains that forensic firearm identification involves examining a firearm, test-firing it to generate known standards, and then comparing these standards to submitted evidence like cartridge cases and bullets. Markings on fired components are caused by direct contact with the firearm's internal surfaces during discharge, allowing for identification based on unique scratch marks.

Class and Individual Characteristics
00:09:16

He further explains class characteristics as predetermined features by the manufacturer (e.g., firing pin shape, barrel rifling width and twist direction) and individual characteristics as unique wear and tear specific to a single firearm (e.g., tooling imperfections, corrosion, erosion), which develop over time with use.

Laboratory Procedures for Comparison
00:12:18

Mr. Jey describes the lab process, including using a stockpile of ammunition to test-fire submitted firearms into a bullet recovery trap to obtain known standards. These known standards are then compared to questioned items using a comparison microscope, which allows for simultaneous viewing and superimposition of items to identify visual correlations in markings.

Evidence in the Emily Faso Case
00:14:32

Mr. Jey details the items received for the case involving Emily Faso's death: a 9mm Glock 19 pistol with an aftermarket Silentco barrel, a compatible Silentco silencer, a bullet jacket, a bullet core, a fired bullet, a magazine, and several cartridges.

Stipulation of Evidence Chain of Custody
00:15:28

Stipulation number nine is read, confirming that various items, including a partial projectile, the Glock 19 firearm, a magazine with ammunition, and several other projectiles and a cartridge casing, were collected, analyzed by Harry Jey, and their chain of custody is not being challenged.

Examination of the Glock 19 Firearm and Silencer
00:23:21

Mr. Jey explains the examination process for the firearm (State's 79), including unsealing the evidence box, photographing the firearm, verifying the serial number, and recording unique details like make, model, type of magazine, and safety systems. He identified it as a Glock 19 with an aftermarket Silentco barrel. He confirms the safety features were working and tests the Silentco silencer (State's 52a), noting it threads onto the barrel easily. He also clarifies that the silencer can fit other similarly threaded barrels.

Impact of Silencer on Markings and Test Firing
00:30:11

When asked if a silencer affects bullet markings, Mr. Jey explains that if the alignment between the silencer and barrel is proper, the bullet typically won't be marked by the silencer. However, he conducts test fires both with and without the silencer to account for potential contact and unusual markings.

Comparison of Bullets and Cartridge Cases
00:32:11

Mr. Jey discusses the comparison of the evidence. He did not compare a bullet core (83a) due to insufficient markings. A fired bullet jacket (91a) had class characteristics consistent with the firearm but lacked sufficient individual markings, resulting in an inconclusive finding. Another complete bullet (84A) also yielded an inconclusive result for similar reasons. However, a fired cartridge case (85a) was positively identified as having been fired from the submitted firearm based on both consistent class characteristics and sufficient individual characteristics.

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