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.

The trial of a former Michigan police officer charged with second-degree murder in the killing of a 26-year-old Black man is set to begin in Grand Rapids, three years after the case sparked weeks of protest and national outrage.