One by one, relatives of the late Walter Scott urged a judge to mete out a significant punishment for Michael Slager, the white former police officer who fatally shot Scott, an unarmed black man, in the back after a 2015 traffic stop.

Through tears, Scott’s family told Slager they felt sorrow for him and the loss his young children would feel in his absence. In the end, a judge sentenced Slager to 20 years in prison, giving the Scott family the justice they had sought ever since a stranger came to them with the shocking video of Scott being killed.

“I forgive Michael Slager. I forgive you,” Scott’s mother, Judy, said as she turned toward her son’s killer. “I pray for you, that you would repent and let Jesus come in your life.”

Sitting just a few feet away, Slager wiped tears from his eyes and mouthed: “I’m sorry.”

The punishment wrapped up a case that became a rallying cry for the Black Lives Matter movement. Slager, 36, is one of only a few police officers to go to prison for a fatal shooting, and his sentence is by far the stiffest since the shootings came under extra scrutiny in recent years.

Attorneys for the former North Charleston officer said he shot the 50-year-old Scott in self-defense after the two fought and Scott grabbed Slager’s stun gun. They said race didn’t play a role in the shooting and Slager never had any “racial animus” toward minorities.

Still, Slager pleaded guilty in federal court to violating Scott’s civil rights. As part of a plea agreement reached in May, prosecutors dropped state murder charges.

“This is a tragedy that shouldn’t have happened,” U.S. District Judge David Norton said.

Slager apologized to the Scott family, calling Scott’s mother and brothers by their names.

“With my actions that day, Walter Scott is no longer with his family, and I am responsible for that,” Slager said. Of their forgiveness, he added: “I am very grateful for that.”

Slager’s emotions stood in stark contrast to his stoic demeanor during his state murder trial when jurors deadlocked over a verdict. He has several weeks to appeal his sentence and will be housed at the Charleston County jail until he’s assigned to a federal prison.

After the sentencing, Judy Scott and Walter’s two brothers told reporters that, while they had made peace with the case, they remained adamant the officer should pay for his crime.

“Who are we not to forgive?” Rodney Scott said.

A bystander recorded the shooting on a cellphone, and it was shared around the world, setting off protests across the U.S. as demonstrators said it was another egregious example of police officers mistreating African-Americans.

Slager fired at Scott’s back from 17 feet (5 meters) away. Five of eight bullets hit him.

The video was seized on by many as vivid proof of what they had been arguing for years: that white officers too often use deadly force unnecessarily against black people.

When the jury failed to reach a verdict in the state murder case, many black people and others were shocked and distressed, because the video seemed to some to be an open-and-shut case. Some despaired of ever seeing justice.

The shooting angered local African-Americans who complained for years that North Charleston police harassed blacks, pulling them over or questioning them unnecessarily as they cracked down on crime. But after the shooting, the Scott family successfully pleaded for calm, asking everyone to let the justice system run its course.

Two months after the shooting, a young white man killed nine black church members in a racially motivated massacre during a Bible study in Charleston. The family members of those victims struck a similar forgiveness tone after that attack.

Before Slager’s sentence was handed down, the judge had to decide whether the shooting amounted to second-degree murder or manslaughter. Norton found that it was murder.

“No matter what sentence I give, neither the Scott family nor the Slager family is going to think that it’s right,” the judge said.

After the shooting, Slager picked up his stun gun and placed it next to Scott. Slager contended he was securing the weapon. Prosecutors think he put it there to bolster his self-defense story.

The judge also found that Slager obstructed justice when he made statements to state police after the shooting.

A pre-sentencing report for Slager found that he committed manslaughter and recommended 10 to nearly 13 years in prison. But the judge was not bound by that review.

If Slager had faced another state trial and been convicted of murder, he could have been sentenced to anywhere from 30 years to life in prison.

Convictions in police officer shootings are uncommon in the U.S. and prison time is even rarer.

South Carolina has been aggressive in charging white officers who shoot unarmed black people. Four have pleaded guilty in state or federal court in the past six years. But only Slager and former state trooper Sean Groubert, who shot a man as he tried to get his wallet during a seat belt violation check, will have been sent to prison. Groubert was sentenced to five years behind bars.

(AP)