Submitted police firearms, which Cahill test-fired to identify the approximately 210 non-9 mm casings and exclude those weapons as sources of the 56 9 mm casings

Cahill testified that he test-fired the submitted police firearms and matched approximately 210 recovered casings to those weapons. He excluded the police weapons, which were .40 and .45 caliber, as sources of the 56 recovered 9 mm casings.