The union blamed the “problems of leadership” on the mayor.
“The members of the Rochester Police Department and the Greater Rochester Community know my reputation and know what I stand for,” Chief Singletary said in his own statement.
“The mischaracterisation and the politicisation of the actions that I took after being informed of MrPrude’s death is not based on facts, and is not what I stand for.”
Chief Singletary, who spent his entire career in the Rochester Police Department, was appointed chief in April 2019. He will stay on through to the end of the month, Ms Warren said. Both the mayor and Chief Singletary are black.
“This is great news,” said Iman Abid, speaking for Free the People ROC, which has held protests since details of Mr Prude’s death emerged.
“It says to the people that people are able to move things and to shape things. The police chief wouldn’t retire if it weren’t for something that he felt he was accountable to.”
But, she said, nightly protests will continue to push other demands, including the resignation of the mayor, defunding and demilitarising of police, and development of a state law barring police departments from responding to mental health crises.
Officers found Mr Prude running naked down the street in March, handcuffed him and put a hood over his head to stop him from spitting, then held him down for about two minutes until he stopped breathing. He died a week later after he was taken off life support.
His brother, Joe Prude, had called 911 seeking help for Mr Prude’s unusual behaviour. He had been taken to a hospital for a mental health evaluation earlier that night but was released after a few hours, his brother told officers.
His death sparked outrage after his relatives last week released police body camera video and written reports they obtained through a public records request.
Seven police officers were suspended a day later, and state Attorney-General Letitia James said on Saturday that she would form a grand jury and conduct an “exhaustive investigation” into Mr Prude’s death.
In a federal lawsuit filed on Tuesday, Mr Prude’s family alleged that it took more than 90 seconds for officers to notice he had stopped breathing because they were chatting and making jokes at his expense.
Mr Prude’s sister, Tameshay, sued as executor of his estate and named the city of Rochester, Chief Singletary and officers involved in the arrest as defendants.
Mr Prude’s family contends his death and a cover-up stem from longstanding police department policy and practice that “condones and encourages officers to use excessive force as a matter of course, and to lie in official police paperwork and sworn testimony to justify their unlawful actions”.
The lawsuit alleges the police department sought to cover up the true nature of Mr Prude’s death, starting with what Ms Warren said was Chief Singletary reporting to her early on that Mr Prude had an apparent drug overdose.
The lawsuit also argues officers used force against Mr Prude at a time when he “obviously posed no threat to the safety of the officers or anyone else”.
“MrPrude was in the midst of an acute, manic, psychotic episode,” the lawsuit states. “Mr Prude was unarmed, naked and suffering. He needed help.”
Police union officials have said the officers were following their training.