Tulsa leaders on Thursday called for a peaceful response to a jury's decision to acquit a white police officer who fatally shot an unarmed black man, and said more must be done to fight racial divisions in Oklahoma's second-largest city.

The comments came after a jury on Wednesday found Tulsa officer Betty Shelby not guilty of manslaughter. She said she shot out of fear Sept. 16 when she killed Terence Crutcher, who had his hands held above his head.

The initial reaction from the community in the hours after Wednesday night's verdict was peaceful. About 100 demonstrators gathered outside the courthouse and some briefly blocked a main street, but police kept a relatively low profile, standing about a block away.

Mayor G.T. Bynum said at a news conference Thursday that he respected the jury's decision, while also calling Tulsa's racial divide the city's greatest moral issue.

"This verdict does not alter the course on which we are adamantly set," he said. "It does not change our recognition of the racial disparities that have afflicted Tulsa historically. It does not change our work to institute community policing measures that empower citizens to work side by side with police officers in making our community safer."

At least four of the 12 jurors were crying as they left the courtroom Wednesday, and they did not look at either Crutcher's family or Shelby. The jury comprised eight women and four men and included three African-Americans.

Crutcher's family was quickly ushered out of the courtroom sobbing and wailing after the decision.

"Let it be known that I believe in my heart that Betty Shelby got away with murder," Crutcher's father, the Rev. Joey Crutcher, said outside the courtroom.

After the verdict, the Rev. Joey Crutcher, father of Terence Crutcher, said, 'I believe in my heart that Betty Shelby got away with murder.' (Sue Ogrocki/Associated Press)

Shelby looked stone-faced when the verdict was read, but her lawyer said she was "elated" with the jury's decision.

"She's ready to get back to her life," defence attorney Shannon McMurray said.

Shelby testified that she fired her weapon out of fear because she said Crutcher didn't obey her commands to lie on the ground and appeared to reach inside his SUV for what she thought was a gun. Crutcher was unarmed.

Prosecutors told jurors that Shelby overreacted. They noted Crutcher had his hands in the air and wasn't combative — part of which was confirmed by police video taken from a dashboard camera and helicopter that showed Crutcher walking away from Shelby, hands held above his head.

Shelby's attorneys argued that in the two minutes before cameras began recording the encounter, Shelby repeatedly ordered Crutcher to stop walking away from her and get on the ground.

Contentious reports of drug use

Shelby also said she feared Crutcher was under the influence of PCP, a powerful hallucinogenic known as Angel Dust that makes users erratic, unpredictable and combative.

An autopsy showed PCP was in Crutcher's system, and police said they found a vial of it in his SUV.

Crutcher's family said police attempted to "demonize" Crutcher over the drug possession to deflect attention from the fact that he wasn't armed. Radio chatter that captured moments before the shooting included an officer saying Crutcher looked "like a bad dude" who "could be on something." The statements outraged Crutcher's family, who said they indicated a racial bias.

The killing of 40-year-old Crutcher was among a spate of officer-involved shootings in recent years that helped galvanize the Black Lives Matter movement and prompted calls for more police accountability.

Marq Lewis, organizer of the local civil rights group We The People Oklahoma, said the verdict was a blow to Tulsa's black community.

"When is it going to stop — just officer-related shootings? When will the police change policy?" he asked.

About 100 protesters gathered in front of the Mayo Hotel after the verdict was read. They chanted: 'No Justice, No Peace. No Racist Police.' (Ian Maule/Tulsa World/Associated Press)

Tulsa has a long history of troubled race relations dating back to a 1921 race riot that left about 300 black residents dead. In 2015, a poorly trained white volunteer deputy, Robert Bates, shot and killed a black man after Bates said he mistakenly reached for his gun rather than a Taser. The shooting led to the departure of the sheriff.

A Tulsa jury convicted the then-74-year-old Bates of second-degree manslaughter and he was sentenced to four years in prison.

Tulsa County District Attorney Steve Kunzweiler charged Shelby six days after Crutcher was killed. An affidavit accused her of "becoming emotionally involved to the point that she overreacted."

Kunzweiler charged Shelby six days after the shooting. An affidavit accused her of "becoming emotionally involved to the point that she overreacted."

Defence attorney McMurray argued that prosecutors rushed to charge Shelby for political reasons, fearing civil unrest like the angry street protests that erupted in Charlotte, N.C., after the fatal shooting of 43-year-old Keith Lamont Scott four days after Crutcher was killed.