article_snippet: Scroll down for video .
article_snippet: A  handgun uses .45-caliber bullets, and prosecutors have argued that based on ballistics evidence, a Glock 21 was the murder weapon.
article_snippet: But Aspinwall said Aspinwall opinion was based on various characteristics of the weapon, including the curvature of back strap, the magazine well and trigger guard. '
article_snippet: In my opinion, the firearm shown in the video stills is a Glock pistol,' Aspinwall said.
article_snippet: Prosecutor Patrick Bomberg, left, questions Kyle Aspinwall, an employee of weapons manufacturer Glock .
article_snippet: Aspinwall testified that a black object appears to be the magazine of a gun.