CORCORAN — A 67-year-old inmate at the Substance Abuse Treatment Facility and State Prison in Corcoran died Thursday, and authorities suspect that his cellmate killed him.

James D. Torres was found unresponsive in his cell shortly after 5 a.m. Despite life-saving measures, he was pronounced dead a short time later, according to a statement from the state Department of Corrections and Rehabilitation.

There was no immediate word on the cause of his death, but it is being investigated as a homicide. His cellmate, Norbert Arres III, was identified as a suspect, the department said.

The Corcoran prison, which opened in 1997, has more than 4,700 inmates in minimum to high security.

Torres was admitted from Sacramento County in 1996 and was serving 50 years for rape of a spouse with force or violence and sodomy with force, according to corrections officials.

Arres, 37, was admitted from Riverside County in 2018 and was serving six years for being a felon or addict in possession of a gun.

The Kings County District Attorney’s Office is assisting prison investigators on the case, officials said.

(Associated Press contributed to this article.)