CORCORAN (CBS13) – A man convicted of killing and mutilating 25 men has died in prison of natural causes, officials say.

The California Department of Corrections and Rehabilitation officials say 85-year-old Juan Vallejo Corona died Monday at an outside hospital. He was serving 25 concurrent life sentences at CSP-Corcoran and had been at the prison since 1992.

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Corona’s crimes have been called one of the most gruesome in US history. Prosecutors said Corona – who was a farm labor contractor with a history of mental illness – killed and mutilated the 25 men using a meat cleaver, machete, double-bladed ax and wooden club.

Juan Corona in 2018. (Credit: CDCR)

Juan Corona in 2018. (Credit: CDCR)

All of Corona’s victims were farm workers. All were at one point seen with Corona, prosecutors said, or had been hired through his labor contracting business.

Prosecutors said Corona buried the remains of the workers on two ranches where he worked near Yuba City.

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For a time, Corona’s spree was the deadliest rampage in the US. Only John Wayne Gacy Jr.’s 1980 conviction on 33 murders of young men and boys in Chicago surpassed Corona’s.

Corona was originally tried and found guilty of the 25 murders in 1973. He was stabbed in an attack at California Medical Facility in Vacaville and lost sight in his left eye.

An appellate court overturned the conviction in 1978, but he was later convicted again for all 25 murders in 1982 after a new trial. He was transferred to CSP-Corcoran in 1992 to their Protective Housing Unit.

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Corona had been denied parole eight times since 1984. He was due for another parole hearing in 2021.