TULSA, Okla. (Reuters) - An Oklahoma jury on Wednesday found a white Tulsa police officer not guilty of manslaughter in the fatal shooting of an unarmed black man in a confrontation caught on video last September, stoking a national debate over racial bias in law enforcement.

Betty Shelby, 43, was acquitted after a week-long trial. She denied race was a factor in the killing and insisted her actions were driven entirely by the behavior of the man she shot, Terence Crutcher, 40, after his car was left blocking a road.

Police videos of the incident were seen globally, and some civil rights advocates have argued that race was a factor. Rights advocates saw the Crutcher case as another in a string of deaths of unarmed black men at the hands of the police in the United States that has spawned periodic protests and the Black Lives Matter movement.

Lawyers for Shelby have said she believed that Crutcher may have been trying to reach through a partially open window for a weapon in the vehicle when she shot him.

“This is a tough pill to swallow. The facts were there. The elements were there. Terence’s hands were in the air. He was not an immediate threat,” Crutcher’s sister, Tiffany, said after the verdict.

Jurors were visibly emotional and some cried when the verdict was read by the judge some nine hours after they began deliberating.

“What I respect is the process. The true reality is that we all knew it was a difficult case,” said Tulsa County District Attorney Steve Kunzweiler who prosecuted the case.

Shelby’s lawyers did not comment to Reuters after the verdict was read.

About 50 protesters gathered outside the courthouse in downtown Tulsa after the verdict was read. They chanted “no justice, no peace” and blocked traffic in an intersection during a peaceful demonstration, media reported.

They also gathered outside a hotel where Shelby was believed to be staying and shouted profanities, the Tulsa World reported.

The case hinged on videos in which Crutcher can be seen with his hands in the air shortly before he was shot. Tulsa police have said Crutcher was unarmed and there was no weapon in his vehicle.

Shelby told the jury that she was taught during training that if a suspect reaches into an area like a car, an officer does not let them pull their arm back because they might be holding a gun, the Tulsa World reported from the court room.

She said the first time she fired her weapon on duty was when she shot Crutcher, who did not speak during their encounter, according to court testimony from officers on the scene.

Prosecutors have said there was no reason for Shelby to fire on a man who was walking away from her. They blame her for turning a routine traffic matter into a deadly confrontation by acting unreasonably and escalating the situation.

The Oklahoma Medical Examiner’s Office said that Crutcher had 96 nanograms per milliliter of the hallucinogenic drug PCP in his bloodstream at the time of his death.

Prosecutors have previously said Crutcher’s drug use was not reason enough for Shelby to resort to deadly force, media reports said.