SACRAMENTO, Calif. (AP) — Officials say a San Francisco Bay Area serial killer has died of unknown causes on California’s death row.

Corrections officials said Friday that 65-year-old condemned inmate Anthony McKnight was found unresponsive in his San Quentin State Prison cell Thursday night and pronounced dead shortly thereafter.

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The cause is awaiting an autopsy, but corrections spokeswoman Terry Thornton says there is no reason to suspect foul play.

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He was sentenced to die after Alameda County investigators linked his DNA to five young women slain in 1985. One was 13 years old. The discovery came after he was already in prison serving a 63-year sentence for rape and attempted first-degree murder.

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Gov. Gavin Newsom earlier this year imposed a moratorium on the death penalty as long as he is governor.