Updated

A sound expert testifying in the case against a Cleveland patrolman says at least one other officer fired a gun during the final volley of a 137-shot barrage that killed two unarmed suspects after a high-speed chase.

The expert testified Monday for the defense at the voluntary manslaughter trial of 31-year-old Michael Brelo (BREE'-lo). Two sound experts who testified for prosecutors reached a similar conclusion: Three other rounds were fired while Brelo fired the final 15 rounds of the 49 shots he shot that night in November 2012.

The experts' testimony could prove significant because prosecutors have said Brelo was the only officer of the 13 who fired that night to be charged criminally because he fired the last 15 rounds after Timothy Russell and Malissa Williams no longer were a threat.