NEW YORK (AP) — The death of a mentally ill, homeless former Marine in a 101-degree New York City jail cell was caused by hyperthermia due to environmental exposure to heat, according to a spokeswoman for the medical examiner, who ruled the February death an accident on Friday.

Antipsychotic medication therapy for treatment of schizoaffective disorder contributed to the death of Jerome Murdough, 56, in a mental observation unit on Rikers Island, said spokeswoman Julie Bolcer.

ADVERTISEMENT

Murdough, who officials have said was not checked on for at least four hours, was found slumped at the foot of his bed with a pool of vomit and blood on the floor in the early hours of Feb. 15 with an internal body temperature of 103 degrees, according to an initial investigation filed this spring in a separate federal lawsuit.

A medical examiner investigator said in those court papers it appeared Murdough had died from hyperthermia.

The Associated Press was first to report on suspicions of Murdough’s death. He died a week after he was sent to Rikers on a misdemeanor trespassing arrest after being unable to pay $2,500 bail. An official, speaking to the AP on the condition of anonymity because the official wasn’t permitted to discuss the case, said at the time Murdough “basically baked to death.”

Murdough had suffered from bipolar disorder and schizophrenia, according to his family, and was on psychotropic drugs that experts say make people on them more sensitive to heat.

Murdough’s mother, 75-year-old Alma Murdough, has announced plans to file a $25 million wrongful death lawsuit over her son’s death.

“With today’s news the Murdough family is calling for a criminal investigation,” said family attorney Derek Sells. “The medical examiner’s findings fully support the family’s view that Jerome’s death was in violation of his civil rights, his human rights and amounts to criminally negligent homicide.” Prosecutors are investigating.

“The safety of inmates and staff is our top priority and we have taken action to ensure that a similar tragedy does not happen again,” a Department of Correction spokesman said.

Murdough’s death and the death of another mentally ill inmate who died after sexually mutilating himself while locked alone for seven days in a Rikers cell last fall have prompted calls for jail reform. City Council hearings were convened to examine violent conditions at the jail complex and treatment of mentally ill inmates.

ADVERTISEMENT

Mayor Bill de Blasio, who has called Murdough’s death “troubling,” also convened a task-force of experts to examine how the mentally ill fare throughout New York’s criminal justice system — before, during and after their time in jail. That task-force is expected to release its findings later this month.

Roughly 40 percent of the 11,5000 daily inmates in the nation’s second-largest jail system have a mental health diagnosis, officials say. About a third of those suffer from serious mental illnesses such as bipolar disorder or schizophrenia.

De Blasio has vowed to improve conditions in the lock-ups, and his new commissioner, Joseph Ponte, has a reputation for transforming troubled jails.