Former North Charleston police officer Michael Slager gestures as he testifies in his murder trial at the Charleston County court in Charleston, South Carolina, November 29, 2016. REUTERS/Grace Beahm/Post and Courier/Pool TPX IMAGES OF THE DAY

A white former South Carolina policeman testified in his murder trial on Tuesday that he felt fear before fatally shooting an unarmed black man last year in an incident that intensified debate about racial bias in law enforcement.

Michael Slager, 35, appeared emotional at times on the witness stand in a Charleston courtroom, in his first extensive public detailing of the April 2015 killing of motorist Walter Scott, 50.

A bystander’s cellphone video appeared to show Slager firing eight times at Scott’s back as he fled after a traffic stop in North Charleston. The recording was shown repeatedly on television and social media.

“My family has been destroyed by this,” said Slager, who recalled missing his son’s birth after being jailed over the shooting. “Scott’s family has been destroyed by this. It’s horrible.”

Dressed in a dark suit, he described how a normal Saturday turned deadly after he stopped Scott for a broken brake light.

Slager said the motorist ran from him, resisting his orders to stop. Slager testified that when he attempted to use a Taser to subdue Scott, they ended up in a scuffle. Scott grabbed his stun gun, the ex-officer said.

Slager said he felt “total fear” as Scott came toward him. He pulled out his gun and opened fire.

“I fired my firearm until the threat was stopped,” he said.

The account by Slager, who was dismissed from the North Charleston Police Department after the shooting, offered a different view from what state prosecutors argue was captured by the bystander’s footage of the incident.

Prosecutors contend Slager did not appear to be in danger when he hit Scott with five shots. They said Scott fled because he was behind on child support payments and feared arrest.

Under cross-examination, a prosecutor accused Slager of changing his story at times. Slager acknowledged that some things clear on the video were not known to him as the incident unfolded.

“My mind was like spaghetti,” he said, noting he was tired after running and fighting Scott on the ground.

After hearing from Slager and several others, the defense rested its case late on Tuesday. Testimony began early this month before a jury of 11 whites and one black. Slager faces a maximum of life in prison if convicted.

Slager said that looking back, with facts he since has learned, he would not have left his patrol vehicle to chase Scott.

“Things could have been different,” he said.

(Reporting by Letitia Stein in Tampa, Fla.; Editing by Colleen Jenkins, Peter Cooney and Andrew Hay)