LOS ANGELES — A California inmate serving a life sentence for the murders of seven people is suspected of killing his cellmate in a Kern County prison Friday, the state corrections department said.

Juan Villanueva, 53, was found unresponsive around 8:50 a.m. in the cell he shared with Ramon Escobar at North Kern State Prison, the California Department of Corrections and Rehabilitation said in a statement.

Villanueva was pronounced dead a short time later.

The case is being investigated as a homicide and Escobar, 51, is the suspect, the department said. A cause of death will be determined by the medical examiner’s office.

Escobar is serving life in prison without the possibility of parole after being convicted of five counts of murder. He pleaded guilty to most of the charges and no contest to the fifth in 2022, according to court records.

Several of the victims were homeless and were beaten to death, officials have said. He beat and robbed other victims as well, prosecutors said at the time. Some of the victims were attacked as they slept, and Escobar used a bat or blunt object.

Escobar, who is originally from Texas, also pleaded guilty to murder in the deaths of his uncle and aunt in that state, NBC affiliate KPRC of Houston reported at the time.

Villanueva was serving a sentence of life with parole for aggravated sexual assault of a child under 14 years old, the Corrections Department said.

He was sentenced in 2022 and transferred to the department’s custody on Feb. 2.

Escobar has been moved to restricted housing pending the outcome of the investigation, a spokesperson for the department said.