Recordings from police body cameras show how Daniel Prude was forced to lie on the ground with a spittoon and handcuffs.
He was held for several minutes and stopped breathing.
His brother had called the police for help as Daniel Prude was mentally unstable.
When police arrived at the scene, he ran naked along the street.
In a legal document, Daniel Prude's family emphasizes that it took over 90 seconds for the police to discover that Daniel Prude had stopped breathing, as they were busy talking to each other and joking at his expense.
"He was unarmed, naked and unwell.
He needed help ", it says in the document, according to AP.
After receiving life-sustaining treatment in hospital for a week, Daniel Prude died.
Led to protests
Seven police officers who took part in the arrest were previously fired, but the fact that it only happened six months after Daniel Prude's death has attracted criticism.
The chief of police and the deputy chief of police in Rochester are resigning as a result of the incident, reports AP.
The incident occurred in March in Rochester, New York.
But it is only now in early autumn that the information about Daniel Prude's death has been published by family members and activists.
Since then, protests have been held in Rochester and in New York City.
- This is fantastic news.
This shows that people have the opportunity to influence and make things happen.
The police chief would not have resigned if it were not for the fact that he feels responsible, says a spokesman for the organization Free the people ROC, to AP.
"An attempt to ruin my career"
The police chief has given a comment in a statement.
- The events of the past week are an attempt to destroy my career and my integrity.
The Rochester police and community know my reputation and what I stand for.
The wrong image and politicization of the measures I took after receiving the information about Daniel Prude's death is not based on facts and does not represent what I stand for.