A Los Angeles serial killer who bludgeoned his victims with a baseball bat is suspected of killing his cellmate on Friday at North Kern State Prison in Kern County.

Ramon Escobar, 51, shared a cell with Juan Villanueva, who was serving a life sentence for aggravated sexual assault of a child under 14, according to the California Department of Corrections and Rehabilitation.

Villanueva, 53, was found unresponsive in his cell at 8:49 a.m. and pronounced dead a short time later, authorities said.

Prison officials have restricted movement in the area where the attack occurred so the investigation can proceed.

The coroner’s office will release Villanueva’s cause of death.

Escobar is serving life without parole.

He admitted to killing his uncle and aunt in Texas before fleeing to California, where in 2018 he bludgeoned five people to death and injured several others, many of them homeless, in attacks that occurred in Los Angeles and Santa Monica.

Escobar, originally from El Salvador, was deported six times before the killings, officials said.