Denver District Attorney Mitch Morrissey has declined to press criminal charges against a Denver police officer who shot and killed a Native American man in July. The man, Paul Castaway, holding a knife to his own throat and threatening to kill himself, was walking toward officers when Officer Michael Traudt fired three shots toward Castaway, two of which hit him in the midsection. Along with a nine-page report explaining his decision, Morrissey on Monday released surveillance footage of the shooting.

The shooting spurred protests in Denver this summer, as Castaways’ family disputed the initial police account that claimed Castaway, 35, came “dangerously close” to officers with a knife. At the time, they said officers didn’t have to shoot him, and he was clearly mentally ill and in need of help. People in Castaway’s family said they’d seen the video shortly after the shooting, and said it showed him holding the knife to his throat—not pointing it in the direction of the police.

Lynn Eagle Feather, Castaway’s mother, blasted Morrissey’s decision. “I don’t think it’s right,” she told Mother Jones on Monday. “Because the Denver Police have been getting away with killing so many young people. Yeah my son had a knife to his throat, but he was more of a threat to himself than he was to the police.”

According to Morrissey’s report, officers were deployed to Eagle Feather’s apartment after she called and told the police that her son had arrived, “mentally ill and drunk.” She said she had been watching her grandchildren, and that her son had poked her in the neck with a knife, so she took the kids to a building across the street for safety. When the police arrived, they talked to Eagle Feather there and then went back to her apartment to see if her son was still around. As they escorted the mother back to her home, the officers spotted Castaway, who began running.

The officers chased him to a nearby trailer park, where they cornered him between a fence and a minivan. Castaway turned around, with the knife to his own throat, while walking in the direction of the officers. The surveillance footage shows the officers backing up as Castaway walks toward them with the knife still to his throat. According to Traudt, Castaway “started to move the knife from his throat toward me, and he didn’t stick it out, but he brought it down, and he was walking at me just aggressively and he wouldn’t stop, and I didn’t feel like I could back up anymore.”

Castaway had his back to the surveillance camera that captured footage of the shooting, so it’s impossible to tell whether the knife was actually coming away from his neck. The video also shows a lot of bystanders in the area, including several children.

“I called for help,” Eagle Feather said. “I didn’t call for a killing. And I can never get my son back.”

Eagle Feather told Mother Jones that the police need more training on how to deal with the mentally ill. She said she’s considering legal action against the Denver Police Department. The city of Denver has paid out more than $10 million in the last four years related to excessive police force, according to the Colorado Independent.

Morrissey said his decision was based on the law.

“In this case, Castaway’s decision to turn, confront the officers and deliberately advance toward Officer Traudt, knife in hand, rather than complying with his orders, compelled Officer Traudt to shoot,” Morissey said in the report. “The surveillance video clearly depicts Castaway moving quickly and purposefully toward Officer Traudt. Castaway’s actions and the statements he made suggest he had decided to die and further decided that Officer Traudt would be the instrument of his demise.”

This article has been revised.