Three US police officers in Colorado have been sacked after they shared photos re-enacting a chokehold used on a black man who later died.
Elijah McClain, 23, died in August last year after being stopped by police.
Another officer resigned over the matter. A local police chief called the images "beyond comprehension".
Mr McClain's case attracted renewed focus in the wake of the death of George Floyd, another unarmed African-American who died in police custody.
The officers who were fired were named as Jason Rosenblatt, Erica Marrero and Kyle Dittrich. The fourth, Jaron Jones, resigned on Tuesday.
Vanessa Wilson, the acting police chief in Aurora, where the incident took place, called the images a crime against humanity and decency.
"We are ashamed, we are sickened, and we are angry about what I have to share," she told a news conference.
"While the allegations of this internal affairs case are not criminal, they are a crime against humanity and decency. To even think about doing such a thing is beyond comprehension and it is reprehensible."
One of the pictures shows former officers Dittrich and Jones imitating a neck hold, while Marrero smiles to their left.
Jason Rosenblatt was sent the photos by text and responded "ha ha".
Chief Wilson said she held off releasing the photos until she could share them with Mr McClain's family. Their lawyer called the images "appalling".
What happened to Elijah McClain?
Mr McClain was walking in Aurora on 24 August last year when he was stopped by three police officers.
A district attorney report later said there had been an emergency call about a "suspicious person" matching his description.
There was a struggle after Mr McClain resisted contact with the officers, who wanted to search him to see if he was armed, the report says. On body cam footage Mr McClain can be heard saying, "I'm an introvert, please respect my boundaries that I am speaking."
One of the officers then says "he is going for your gun", and they wrestle him to the ground and put him in a chokehold.
The report says Mr McClain lost consciousness, was released from the chokehold, and began to struggle again.
The officers called for assistance, with fire fighters and an ambulance responding. A medic injected Mr McClain with ketamine to sedate him.
Mr McClain was then put in "soft restraints" on a stretcher and put inside the ambulance. The medic who had administered the drug then noticed that Mr McClain's chest "was not rising on its own, and he did not have a pulse". He was declared brain dead on 27 August.
Mr McClain's family allege that the officers used excessive force for about 15 minutes as Mr McClain vomited, begged for them to stop and repeatedly told them he could not breathe. The officers also threatened to set a police dog on him, the family said.
An coroner's autopsy found the cause of death to be undetermined.
Colorado Governor Jared Polis has appointed a special prosecutor to review the case. Earlier this month, Aurora police banned the chokehold used on Mr McClain. New rules also say officers must intervene if they see a colleague using excessive force.