LOS ANGELES -- James Lee Crummel, a pedophile and convicted killer sentenced to die for the 1979 murder of a teenage boy, has hanged himself on California's death row, months before voters in the state are due to decide whether to abolish the death penalty, prison officials said on Tuesday.

The 68-year-old was found hanging in his cell at San Quentin State Prison, California Department of Corrections and Rehabilitation spokesman Sam Robinson said in a written statement.

He was pronounced dead at 4:20 p.m. local time (8.20 p.m. ET) on Sunday, Robinson said.

Crummel had been housed on death row since he was sentenced to death in 2004 for the 1979 kidnapping, sexual abuse and murder of 13-year-old James Wilfred Trotter.

Trotter was snatched as he walked to meet his school bus in Costa Mesa, California, in April of 1979. His charred remains were found more than a decade later, in 1990, but not confirmed as that of the boy until 1996.

Crummel was also convicted in San Bernardino County, California, for molesting three boys in Big Bear City, and was suspected of abducting and killing 9-year- old Big Bear Lake resident Jack "J.D." Phillips, who disappeared near his home in 1995, the San Bernadino Sun newspaper reported. 

It said Jack's remains have never been located, and his father said in June 2004 that Crummel refused to disclose to authorities where the boy's remains were located unless the death penalty was taken off the table.

The suicide comes ahead of a ballot measure in November which asks voters to repeal the death penalty in California, home to nearly a quarter of the nation's death row inmates.

The ballot initiative focuses on the high cost of the death penalty in a state that has executed 13 people since capital punishment was reinstated in the nation in 1976. More than 720 inmates sit on death row pending lengthy and expensive appeals.

Crummel joins another 20 inmates who have committed suicide while on California's death row. According to the corrections department, since capital punishment was reinstated in California in 1978, 57 condemned inmates in the state have died from natural causes and six died from other causes.

A federal judge halted all California executions in 2006 after ruling that the three-drug protocol that has been used for lethal injections carried the risk of causing the inmate too much pain and suffering before death.

California has since revised its protocol but an appeals court has blocked resumption of executions over the same objections.

A 1997 profile of Crummel and the detective who helped secure a key conviction against him, was re-published by the Orange County Register on Wednesday.

Reuters contributed to this report.

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