The 911 call came during the early hours of Nov. 15: Dustin Pigeon told the dispatcher he wanted to kill himself, but he didn't say how, according to prosecutors.
Officers rushed to a subdivision near southwest Oklahoma City. They found the 29-year-old alone in a courtyard, a white bottle of charcoal lighter fluid in one hand, a Bic lighter in the other.
Two officers tried to talk him down, telling him to drop the bottle and raise his hands, as shown in body camera footage from the scene. Pigeon complied.
Then a third officer, Sgt. Keith Sweeney, approached and issued commands. "I will (expletive) shoot you! Get on the ground!" he screamed, prosecutors say.
One officer fired a bean bag round at Pigeon, trying to incapacitate him. A split-second later, Sweeney opened fire with his service weapon, striking Pigeon multiple times, according to authorities. He died on the scene.
On Tuesday, prosecutors charged Sweeney, of the Oklahoma City Police Department, with second-degree murder in the death of Pigeon, whom they say was suicidal and trying to set himself on fire when he was gunned down. They also filed an alternative charge of first-degree manslaughter.
District Attorney David Prater said in a news conference that Pigeon was unarmed and posed no threat to the officers when Sweeney fired five rounds at him. The other two officers had already begun "textbook" deescalation tactics when Sweeney arrived, he said, and the sergeant should have followed their lead.
"Sweeney should not have been yelling orders," Prater said. "You don't want a third officer coming in, you don't want three different people giving different commands."
"That confuses people, especially when they're in a state of mind like Mr. Pigeon was."
The district attorney added that Sweeney had indicated in his statement on the incident that he didn't hear the bean bag shot from his fellow officer and therefore wasn't engaging in "sympathetic fire" when he shot Pigeon.
Sweeney, 32, was arrested and booked on Tuesday. It wasn't immediately clear if he had retained a defense attorney. He is a nine-year veteran of the department.
The head of the city's police union urged people to suspend judgment while the case proceeds.
"Police officers are routinely placed in dangerous situations where they must quickly make life-or-death decisions," John George, president of the Oklahoma City Fraternal Order Police, said in a statement. "We caution citizens against jumping to conclusions until the facts are fully presented."
Prater, too, stressed that Sweeney was innocent until proven guilty. When investigators asked Sweeney why he had fired his service weapon, he told them he thought Pigeon was holding a knife in his hand and felt his life was in danger, according to the district attorney.
"It will be a jury's decision and duty to determine exactly the truth and veracity of that statement," Prater said.
In Tuesday's news conference, Prater released body camera footage from the two officers who responded to the scene with Sweeney. If the videos paint an accurate picture, the officers had been on the scene for less than a minute when Sweeney opened fire.
The courtyard is dark as the officers get out of their cars and shine their flashlights across the grass. Pigeon can be seen standing in front of a small one-story house, wearing blue jeans and a dark T-shirt. A white canister is clearly visible in his left hand.
"He's got lighter fluid in his hand?" one officer asks his partner. Then he calls out: "Hey, put it down."
"Come here man, stop it," the other officer says in a stern but calm voice. "Let me see your hands, bud."
"Back off me," Pigeon says, then raises his hands. "My hands are up."
"Put the lighter fluid down, bud," the officers tell him.
The officer identified by prosecutors as Sweeney then approaches from the left. "Drop it! Drop it right now!" he screams at Pigeon. "I will (expletive) shoot you! Get on the ground!" (The profanity is bleeped out in the video distributed to the press but was described by prosecutors.)
Gunfire erupts. Pigeon collapses to the ground, groaning in pain.
"Is that a knife in his hand?" the officer identified as Sweeney asks.
"That's lighter fluid," one of the other officers responds.
Prater praised the way the way Sweeney's fellow officers handled the situation, saying they had followed their training to bring the situation to a peaceful solution. He said Sweeney was the only one who arrived with his gun drawn.
"You see officers doing exactly the right thing almost every single time," Prater told reporters. "This is one of those situations, though, where we've alleged that an officer crossed the line and in fact broke the law."
Police are rarely charged in fatal shootings in the line of duty, and prosecutors do not win convictions in most cases. Pigeon is among at least 909 people who have been shot and killed by police so far in 2017 and the 24th person to die by police gunfire in Oklahoma, according to a Washington Post database on such killings. Mental illness has played a role in nearly a quarter of all police shootings nationwide this year, The Post's research shows.
Pigeon's mother, Aronda Pigeon, said Tuesday she was "shocked" to find out that the officer had been charged with murder. "They are at fault," she told the Oklahoman. "The officer is guilty and I want justice for my son."
His aunt, Angela Pigeon, told the newspaper he was a generous person who would give needy neighbors food and kitchen utensils. "He was good about helping people and doing things for others," she said.
Pigeon's father, Boston Pigeon, told News 9 last month that he was struggling to understand why his son was gunned down.
"He went out and helped people. He just was not a mean man. He was not," he said. "He was a good person."