GRAND RAPIDS, Mich. (AP) — The Michigan police officer who allegedly killed Patrick Lyoya, a Black man who was on the ground when he was shot in the back of the head, was charged Thursday with second-degree murder.

Prosecutor Chris Becker announced charges Thursday against Grand Rapids Officer Christopher Schurr, weeks after Lyoya was killed following a chaotic traffic stop on April 4.

The 26-year-old Lyoya was on the ground when he was killed. The shooting was recorded on video by a bystander.

“The death was not justified or excused … by self defense,” Becker said, referring to an element of second-degree murder.

Schurr, who is white, told Lyoya that he stopped his car because the license plate didn’t match the vehicle. Roughly a minute into the stop, Lyoya began to run after he was asked to produce a driver’s license.

Schurr caught him quickly, and the two struggled across a front lawn. The officer demanded that Lyoya “let go” of Schurr’s Taser before he fired the fatal shot.

Becker said he consulted experts from outside Michigan about the use of force in the case.

Attorney Ven Johnson in Detroit with at least one member of Lyoya’s family present said the prosecutor called Johnson and the family about two minutes before making the announcement that the officer is being charged.

“You will not see any celebration on behalf of the Lyoya family,” Johnson said.

The Grand Rapids police chief released video from four different sources on April 13. Attorneys for Lyoya’s family have called the death an “execution.”

Grand Rapids, population about 200,000, is 160 miles west of Detroit.

Schurr has been a police officer since 2015. His personnel file shows no complaints of excessive force but much praise for traffic stops and foot chases that led to arrests and the seizure of guns and drugs.

The shooting turned into an immediate crisis for police Chief Eric Winstrom, who was a commander in Chicago before taking charge in Grand Rapids early in March.

At a community forum in April, Winstrom said he wanted to put more emphasis on officers knowing how to turn down the heat during tense situations.

“I guarantee that we can do more,” he said. “Actually, that’s one of the things I’ve already reached out to my colleagues to say, ‘Hey, I need some curriculum, because we are going to beef it up.’”