COALINGA, Calif. (AP) – Authorities say the death of a 60-year-old inmate at a central California prison is being investigated as a homicide.

The state Department of Corrections and Rehabilitation says guards found Joseph Saucedo unresponsive Friday on the floor of his cell at Pleasant Valley State Prison. He was pronounced dead a short time later.

Officials say guards went to the cell after Saucedo’s cellmate, Jesus Castaneda, declined to go to the recreational yard.

No other details about the death have been released.

Saucedo was locked up since 1997 after receiving a 40-years-to-life sentence for multiple crimes including lewd and lascivious acts with a child.

The 38-year-old Castaneda began serving a life-with-parole sentence in 2017 for first-degree murder.