OTAY MESA, San Diego — Sirhan Sirhan was returned to prison Sunday after the assassin of Sen. Robert F. Kennedy was stabbed at the Richard J. Donovan Correctional Facility, according to news reports.

Various news outlet reported Sunday that Sirhan was moved from the hospital back to Donovan, citing Sirhan's New York lawyer Laurie Dusek and his brother Munir Sirhan, who lives in Pasadena.

The California Department of Corrections and Rehabilitation confirmed an assault on an inmate at 2:21 p.m. Friday. The inmate believed to be Sirhan was found with stab wounds and taken from the prison in Otay Mesa to a hospital.

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The inmate suspected of stabbing Sirhan, whose name was not immediately released, was placed in the prison's Administrative Segregation Unit, pending an investigation, according to the department.

Sirhan was convicted in 1969 of killing Kennedy after the New York Democrat addressed supporters at the Ambassador Hotel in Los Angeles following his victory in the California presidential primary in 1968.

His death sentence was reduced to life in prison after the California Supreme Court ruled in 1972 that capital punishment violated the state Constitution's prohibition against cruel and unusual punishment.