LANCASTER, Calif. (AP) — An inmate at a Southern California state prison has been stabbed to death and another inmate is being held as a suspect, authorities said Friday.

Employees on Tuesday spotted 55-year-old Timothy Johnson applying pressure to his bleeding neck at California State Prison in Los Angeles County.

READ MORE: ‘Shut Up And Make Babies’: Protesters Reveal Deeply Personal Stories Following SCOTUS Decision

He died hours later at a hospital.

Johnson was serving a life sentence for repeated burglaries in San Bernardino County.

READ MORE: California Abortion Activists React To The End Of Roe V. Wade

Investigators named inmate Noel Mayorga, 44, as a suspect in the killing.

Mayorga is serving a nearly 33-year sentence. He was convicted in Riverside County of gross vehicular manslaughter while intoxicated and DUI resulting in the death of more than one victim.

MORE NEWS: Tesla Fire In Alameda County Grows To Over 500 Acres

The prison in Lancaster, north of Los Angeles, houses about 3,200 inmates.