NEW YORK (CBSNewYork) — An investigation was under way Friday into the case of a man who died in police custody last month, after being restrained by officers as he allegedly tried to fight them.

The New York City Medical Examiner’s office has ruled the death of the man, Ronald Singleton, was a homicide, caused by his being restrained by police while in a delirious state caused by PCP. The Medical Examiner said Singleton’s “exciting delirium” was due to “acute phencyclidine intoxication.”

Heart disease and obesity were considered contributing conditions, police said.

Shortly after midnight on Saturday, July 13, a uniformed officer was on foot patrol assigned to St. Patrick’s Cathedral, at 51st Street and Fifth Avenue in Midtown, police said. He was approached by a yellow cab driver, who claimed to have a man in his back seat who was acting “overly irate and irrational, cursing and screaming and causing alarm,” police said.

When the man — identified as Singleton — got out of the taxi, he became combative with the officer on the scene and tried to fight with him, police said.

Other officers responded and restrained the man with “protective body wrap,” police said. Singleton was not placed under arrest, but he was placed in an ambulance headed for to Bellevue Hospital as an emotionally disturbed person, police said.

Singleton went into cardiac arrest while in the ambulance, and the ambulance in turn was redirected to St. Luke’s-Roosevelt Hospital where Singleton was pronounced dead, police said.

Researchers at the University of Miami say the drug-induced episode can trigger super-human strength and immunity to police control tactics like pepper spray and batons. According to researchers, body temperatures increase as the struggle continues and within minutes of restraint, vital signs are gone, WCBS 880’s Jim Smith reported.

Police said Friday that they will continue to cooperate with the Manhattan District Attorney’s office, which will be the lead investigating agency in the case.

You may also be interested in these stories:

[display-posts category=”news” wrapper=”ul” posts_per_page=”4″]