VACAVILLE, Calif. (KTLA) -- Gregory U. Powell, one of the infamous "Onion Field" cop killers, has died in prison, according to the California Department of Corrections. He was 79.
He died on Sunday at the California Medical Facility in Vacaville after a battle with prostate cancer.
Powell was convicted of murdering 31-year-old LAPD Officer Ian Campbell in a crime detailed in former LAPD Officer Joseph Wambaugh's best-selling book, "The Onion Field," which was later made into a movie.
Campbell and partner Karl Hettinger were abducted at gunpoint by Powell and Jimmy Lee Smith on March 9, 1963, while the two officers were patrolling in Hollywood.
The officers were driven to an isolated onion field, where Powell shot Campbell to death.
Hettinger was shot at as he fled the onion field, but managed to escape in the darkness.
Powell was arrested the night of the murder, and his partner, Jimmy Lee Smith, was arrested the next day.
Both were convicted of murder and sentenced to death, but their sentences were commuted to life in prison after California's death penalty was declared unconstitutional in 1972.
In 1982, both Smith and Powell were scheduled for release, but only Smith got out.
Powell's parole was revoked after a public outcry spurred in part by a television broadcast of the movie "The Onion Field," in which Powell was portrayed by actor James Woods.
Powell was denied parole 11 times, most recently in January 2010, when he told a panel of the California Board of Prison Terms that he had terminal cancer and wanted to be freed before he died.
In October 2011, the board denied his request for compassionate release.
"To have released the man who kidnapped and callously executed Officer Ian Campbell would have been a travesty of justice," L.A. County District Attorney Steve Cooley said in a statement at the time.
Smith died in 2007 in a Los Angeles jail, where he was being held after one of many parole violations.