One of Kern County's most infamous killers died in his prison cell from natural causes Tuesday night.

David Leslie Murtishaw, 54, had spent more than half his life on death row for the 1978 murders of three student filmmakers in the Mojave Desert. His death penalty sentence was reversed twice and he was resentenced to death both times.

His conviction had always been affirmed.

Former Kern County District Attorney Ed Jagels, who prosecuted Murtishaw's last retrial, said Wednesday he decided to retry Murtishaw even after two reversals because it was clearly a case in which the death penalty was warranted.

"First of all, it was one of the most brutal, coldblooded crimes that I've ever experienced in 35 years as a prosecutor," Jagels said. "He simply systematically executed three totally innocent people begging for their lives, and almost killed a fourth."

Jagels said Murtishaw's sentence was reversed twice for "preposterous reasons" by judges who were against the death penalty. He said it's a measure of the dysfunction of the criminal justice system that Murtishaw died a natural death rather than being executed.

"All I can say is that his death didn't come soon enough," Jagels said.

Murtishaw encountered the USC students near Highway 14 and the Randsburg cutoff on April 9, 1978 as they were filming, according to The Californian archives. His car broke down and he asked for a ride, and the students told him he would have to wait until they finished filming.

Murtishaw left, but later returned and fired at the students until his .22-caliber rifle was empty, the archives said. He then reloaded and fired again.

Killed were Ingrid M. Etayo, 22, James Lee Henderson, 24, and Martha Bernice Soto, 22. The attack's lone survivor, Lance Wyatt, was Soto's husband.

Wyatt, whose last name was Buflo back then, escaped with a hand wound. He later testified in the trial and both retrials.

Murtishaw was first sent to San Quentin State Prison on May 1, 1979. He was resentenced in 1983 and 2002.

The California Department of Corrections and Rehabilitation reported Wednesday that 55 death row inmates have died of natural causes since capital punishment was reinstated in 1978. Thirteen condemned inmates in the state have been executed in California, one in Missouri, and 19 have committed suicide.

Six died from other causes, the CDCR reported. As of Wednesday, there were 718 inmates on California's death row.

The Los Angeles Times cited CDCR officials saying Murtishaw died of an apparent heart attack.