SALEM, Mass. (AP) — The death of a Massachusetts man this summer outside a fish market was attributed to an abnormal heartbeat caused by cocaine and alcohol intoxication and efforts by police to restrain him, the prosecutor’s office said Friday.

The July 11 death of Francis Gigliotti was deemed to be a matter of homicide in the medical examiner’s findings provided to Essex County District Attorney Paul F. Tucker office Thursday, the Salem-based prosecutor said in a statement.

Tucker’s office is investigating “whether the actions of the police officers were justified,” according to the statement.

Seven officers in Haverhill, north of Boston near the New Hampshire line, were put on paid leave after the handcuffed man became unresponsive and died as he was restrained in a prone position. Gigliotti had been walking into traffic during what his fiancee described as a mental health crisis.

The officers were not wearing body cameras, but video captured by witnesses showed officers holding Gigliotti face down as he cried out. It was unclear how long he was restrained or when he became unresponsive.

The U.S. Department of Justice has warned police officers for decades to roll suspects off their stomachs as soon as they are handcuffed because of the danger of positional asphyxia. Many policing experts agree that someone can stop breathing if pinned on their chest for too long or with too much weight because it can compress the lungs and put stress on the heart.