The actions of first responders in Annapolis, Maryland, are under investigation after a medical examiner ruled a man who died in their custody was killed.

Renardo Green, 51, died of a heart attack June 4 after he was restrained while in the custody of the Annapolis police and Fire/EMS.

Months later, Maryland’s chief medical examiner ruled the manner of the Eastport man’s death was a homicide. Bruce Goldfarb, with the medical examiner’s office, confirmed the ruling was made in September.

Tia Lewis, with the state’s attorney’s office, has confirmed that the matter is under investigation.

As first reported by the Capital Gazette, police responded to Green’s apartment and restrained him, but it reports the autopsy notes that Green had a number of drugs in his system, including PCP, and was strapped face-down to a gurney in the ambulance, which prevented him from breathing.