A Michigan police officer who killed a man with a shot to the back of the head testified in his own defense Friday, telling jurors at his second-degree murder trial that he was "running on fumes" and fearing for his life after losing his Taser during an intense fight.

Testimony from witnesses called by the defense continued Friday in the trial of Christopher Schurr, the former Grand Rapids police officer charged in the shooting death of Patrick Lyoya.

The long-delayed jury trial of former Grand Rapids police officer Christopher Schurr began on Monday in the Kent County Courthouse with the prosecution presenting evidence and witnesses supporting the charge of second-degree murder in the execution-style killing of 26-year-old Lyoya,