A 43-year-old father was shot dead by Las Vegas police in his own home after calling 911 because of an intruder.
Brandon Durham called police after midnight on November 12 and said people had broken into his home and were shooting.
When officers arrived at the scene, they found Mr Durham struggling to wrestle a knife from a woman with a hoodie.
Bodycam footage released by the department showed officer Alexander Brookman, 26, shouting “drop the knife” and immediately opening fire on Mr Durham.
While the father was on the floor, he was then shot by Bookman five more times.
The officer has been put on administrative leave while an investigation is ongoing, said Las Vegas Metropolitan Police.
Police have arrested the woman Mr Durham was attempting to take the knife from, Alejandra Boudreaux, 31.
At a press conference, Dori Koren, the assistant sheriff, said Ms Boudreaux and Mr Durham had previously been in a domestic relationship before the break-in.
After the shooting, she told the officer he shot the wrong person, according to an arrest report.
Ms Boudreaux told police that her relationship with Mr Durham was casual and that they had met recently on a dating app.
According to her arrest report, she said she was suicidal at the time she broke into the house and wanted to be killed by police, saying: “I wanted the cops to shoot me dead. And I wanted [Durham] to live the wreckage that I caused in his house.”
Mr Durham’s 15-year-old daughter was home at the time of the break-in. She told local media she was “disgusted” by the police’s actions.
Lee Merritt, a civil rights attorney representing the Durham family, called for an arrest warrant to be issued for the officer who shot him immediately.
“Brandon was found in his hallway to his bedroom, in his underwear, asking for help while an assailant attempted to stab him using a large knife,” Mr Merritt said.
He was not directing deadly force at anyone and there was no justification for police to use deadly force against him, he said.
But a lawyer representing the officer, David Roger, resisted the call, saying in a statement to CNN: “While Mr. Durham’s death is tragic, Officer Bookman was doing his job and did not intend to commit a crime.”