SAN QUENTIN (CBS SF) — A handyman convicted in the hatchet murders of an elderly couple who employed him and who was sent to San Quentin’s death row has died at an outside hospital early Wednesday morning.

Thomas Potts, 71, was sentenced to death for the murders of Fred and Shirley Jenks of Kings County and had been on death row since July 29, 1998. Prosecutors said the motive was robbery of Shirley Jenks’ jewelry, some of which was pawned later.

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His cause of death is unknown pending the results of an autopsy. The California Department of Corrections and Rehabilitation said however that foul play is not suspected.

Last year, the California Supreme Court affirmed Potts’ sentence after years of appeals, the ruling coming two weeks after Gov. Gavin Newsom placed a moratorium on executions and said he was advocating for the repeal of capital punishment in the state.

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In an unusual opinion which accompanied the ruling, Associate Justice Goodwin Liu said the death penalty system in the nation’s most populous state is dysfunctional and expensive, and a ballot measure approved by voters to speed up executions will not make it workable.

There are currently 728 inmates on California’s death row.

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The CDCR says since California reinstated capital punishment in 1978, 82 condemned inmates have died from natural causes, 27 have committed suicide, 13 were executed in California, one was executed in Missouri, one was executed in Virginia, 14 have died from other causes and six – including Potts – are pending a cause of death.