A jury found Aaron Dean guilty of manslaughter in the death of Atatiana Jefferson, killed during a police welfare check.

Jurors found Aaron Dean not guilty of murder but convicted him of manslaughter in the death of Atatiana Jefferson. The conviction comes more than three years after the white Fort Worth officer shot the 28-year-old woman while responding to a call about an open front door.

Dean, 38, faces up to 20 years in prison on the manslaughter conviction. He would face up to life in prison if convicted of murder. The judge told jurors Wednesday that they could also consider a manslaughter charge.

The Tarrant County jury returned the verdict after more than 13 hours of deliberation over two days. That followed six days of testimony and arguments in which the primary dispute was whether Dean knew Jefferson was armed when he shot her. Dean testified that he saw her weapon, while prosecutors alleged the evidence showed otherwise.

The case was unusual for the relative speed with which, amid public outrage, the Fort Worth Police Department released video footage of the shooting that took place on October 12, 2019, and arrested Dean. He’d completed the police academy the year before and quit the force without speaking to investigators.

Since then, the case had been repeatedly postponed amid lawyerly wrangling, the terminal illness of Dean’s lead lawyer and the COVID-19 pandemic.

Dean shot Jefferson after police received a call on a nonemergency line. Al Jazeera reporter Tylor Hicks recently spoke to the neighbour who made the call, James Smith, a retired US Army veteran.

He told Al Jazeera that he noticed that the door to Jefferson’s house was open and her lights were on, so he wanted to ensure that she was OK.

After Smith learned what happened, he said he fought to raise awareness about Jefferson’s death, against the advice of some in his community. A pastor reportedly told him: “You need to let God handle it; let someone pick up the torch.”

“It’s been three years,” Smith replied, “and no one’s picked it up yet.” He feels frustrated by the delays in the murder trial.

Jefferson had been playing video games on the night of the shooting with her nephew, and it emerged at trial that they left the doors open to vent smoke from hamburgers the boy burned.

Bodycam footage showed that Dean and a second officer who responded to the call didn’t identify themselves as police at the house. Dean and Officer Carol Darch testified that they thought the house might have been burglarised and quietly moved into the fenced-off back yard looking for signs of forced entry.

There, Dean, whose gun was drawn, fired a single shot through the window a split-second after shouting at Jefferson, who was inside, to show her hands.

Dean testified that he had no choice but to shoot when he saw Jefferson pointing the barrel of a gun directly at him. But under questioning from prosecutors, he acknowledged numerous errors, again and again conceding that actions he took before and after the shooting were “more bad police work”.

Darch’s back was to the window when Dean shot, but she testified that he never mentioned seeing a gun before he pulled the trigger and didn’t say anything about the weapon as they rushed in to search the house.

Dean acknowledged on the witness stand that he only said something about the gun after seeing it on the floor inside the house and that he never gave Jefferson first aid.

Jefferson’s 8-year-old nephew Zion Carr was in the room with his aunt when she was shot. Zion testified that Jefferson took out her gun believing there was an intruder in the back yard, but he offered contradictory accounts of whether she pointed the pistol out the window.

On the trial’s opening day, the now 11-year-old Zion testified that Jefferson always had the gun pointed down, but in an interview that was recorded soon after the shooting and played in court, he said she had pointed the weapon at the window.