talked to police and neighbors today about this. >> reporter: police say officer matthew mcgowan's body camera recorded everything and that he came under attack. >> i just heard four or five sounds like popping sounds of gun. >> reporter: a police shooting in montgomery village. >> one guy was doing cpr on the guy on the ground. >> reporter: police say officer matthew mcgowan, out on patrol, got the call, a stolen bike. police say he was talking to the man who called police, richard tilly and writing up the report, when suddenly police say tilly attacked officer mcgowan, five years on the force. >> without provocation, and without notice. the complainant lunged at him with an open knife. the two began fighting physically and the officer fell or was knocked down to the ground. at that point, with the struggle still occurring, side arm and fired multiple times at the complainant.