A 30-year-old Navy veteran undergoing a mental health episode was killed after police officers kneeled on the back of his neck for almost five minutes.

According to CNN, Angelo Quinto’s family called the Antioch Police to their home on Dec. 23 to assist with his crisis. His sister, Isabella Collins, reportedly feared that he would hurt their mother. The family said he had been “suffering from anxiety, depression and paranoia for the previous few months.”

Before the cops arrived, Cassandra Quinto-Collins, Quinto’s mother, was holding him close to her chest with her hands gripped around his back and said that “he had already started to calm down.”

Two Antioch police officers arrived at the residence and the family says they made no attempt to try to understand the situation and immediately grabbed Quinto from his mother. “He said, ‘Please don’t kill me,’ as they were putting him on the ground,” his mother told the Los Angeles Times. “They handcuffed him, and one officer put his knee on the back of his neck the whole time I was in the room.”

“I trusted the police because I thought they knew what they were doing,” she added. “But he was actually passive and visibly not dangerous or a threat, so it was absolutely unnecessary what they did to him.”

Quinto eventually lost consciousness and was transported to a local hospital. He was pronounced dead three days later. Quinto-Collins said the cops did not have body cams, but she was able to record part of the incident after her son stopped moving.

On Feb. 18, the family filed a wrongful death claim against the police department. “These Antioch police officers had already handcuffed Angelo but did not stop their assault on the young man and inexplicably began using the ‘George Floyd’ technique of placing a knee on the back and side of his neck, ignoring Mr. Quinto pleas of ‘please don’t kill me,’” said family attorney John L. Burris.

Quinto’s cause of death is still pending, according to the Contra Costa County Sheriff Coroner’s office, and is currently under investigation by the Contra Costa County District Attorney’s office.