Newly released police body camera footage shows the moments leading up to death of an unarmed Texas man who died after calling 911, with officers pinning the man to the ground and mocking him.

Tony Timpa, 32, died in August 2016 after calling 911 for help outside an adult video store in Dallas, Texas.

Timpa was high on cocaine and ran out of the store and into traffic before private security guards handcuffed him before police arrived, according to NBC DFW. He told a dispatcher that he suffered from schizophrenia and depression and was off his prescription medication, according to The Dallas Morning News.

The video footage, which was obtained by The Dallas Morning News and NBC DFW Tuesday and released in part, shows Timpa wailing and screaming for help, repeatedly saying, “You’re gonna kill me! You’re gonna kill me! You’re gonna kill me!”

Video from NBC DFW

Timpa’s death was ruled a homicide by the Dallas County Medical Examiner, who said Timpa died from sudden cardiac arrest caused by the effects of cocaine and stress from being physically restrained.

In the video, the officers pin Timpa down on the floor and hold him there by his shoulders and neck, with the man face down in the grass. Timpa continues to plead with the officers as he is on the ground, but eventually stops making sounds or responding to them.

Timpa was restrained for about 14 minutes, according to NBC DFW.

Tony Timpa Family photo / via NBCDFW

The officers eventually begin asking Timpa to respond, but he remained motionless. One officer says he thought Timpa had nodded in response to the offices questions.

The officers are then seen making fun of Timpa as they joke about waking him up.

“Tony, time for school,” one officer says.

“I don’t want to go to school,” another officer says in a mocking voice and laughing as Timpa lays face-down on the floor motionless.

Another officer is then shown giving Timpa an injection.

Timpa is unresponsive as officers move him onto a stretcher, according to NBC DFW.

“Is he knocked out?” one officer asks in the video.

“He didn’t just die down there did he,” one man asks.

They then begin to question if Timpa is still breathing.

“I hope I didn’t kill him,” one officer says.

Paramedics in the video then notify the officers that Timpa is not breathing.

“He’s dead,” one says.

The Dallas Police Department body cam footage was released after a legal battle by NBC DFW and The Dallas Morning News to obtain the video.

A grand jury indicted three Dallas police officers in 2017, saying they “engaged in reckless conduct that placed Timpa in imminent danger of serious bodily injury.”

But this past March, charges of misdemeanor deadly conduct against three Dallas police officers in connection with Timpa’s death were dismissed by the Dallas County District Attorney. The three officers are back on full duty, according to NBC DFW.

The Dallas Police Department told NBC News the involved officers were removed from administrative leave in April have returned to full-duty status. The department said because of pending litigation, it was "unable to comment further surrounding this incident."