Daryn Javer’s eyes are glued to the comparison microscope as she focuses closer onto the 9-mm Luger cartridge case. She adds more lighting and turns her attention to the nearby monitor, adjusting a split-screen image of her subjects: a discharged cartridge case and a test-fired cartridge case ejected from a known firearm, until she lines up drag marks and breech face marks. With the markings aligned, she merges the pair of circular cartridge cases until they overlay one another on the screen, and she affirms they were fired from the same gun.
Rodrigues, Jill and Wilder, Justin, "A Student's Day Inside the R.I. State Crime Lab" (2018). Featured News Story. 187.