ROCHESTER, N.Y. (WROC) — Disturbing body camera footage was released Wednesday, showing the incidents leading up to Daniel Prude’s death.

Black Lives Matter leaders say Daniel Prude was killed by police back in March. Prude’s brother Joe said he called the police because Prude was having a mental health crisis.

The family received body camera footage of the incident from the city after filing a Freedom of Information request. Joe Prude said his brother was laying down — naked, handcuffed, and unarmed — when officers killed him. He said an officer pushed Daniel’s head into the ground.

“That matter was a call for help, I see you sitting here in a push up stance on my brother’s damn neck. How are you sitting here with your knee in my brother’s damn back when he’s defenseless, he’s got on no damn clothes,” said Joe.

Black Lives Matter leader Stanley Martin said officers also taunted Daniel.

“While cuffed, naked, unarmed, and laying down in the freezing cold ground, RPD officers mocked Daniel Prude, cracked jokes, and put a bag over his head,” Martin said.

She said less than 10 minutes after officers handcuffed him, Daniel was brain dead. He was taken to the hospital and put on life support and later died. According to the autopsy report, Prude’s death has been ruled a homicide. The report says he died from complications of asphyxia due to physical restraint.

“How many more brothers gotta die for society to understand that this needs to stop?” Joe said.

Activists are calling for the immediate firing and arrest of the officers involved and those who were bystanders. They’re also calling to defund the police and to pass a law forbidding police officers to respond to mental health calls.