This undated photo provided by the California Department of Corrections and Rehabilitation shows Gregory Powell, was serving a life sentence for the 1963 killing of Los Angeles Police Officer Ian Campbell.
"Onion Field" killer Gregory Powell, who abducted a pair of Los Angeles police officers in 1963 and killed one of them, has died in prison after a bout with terminal prostate cancer.
Powell, 79, died Sunday at the California Medical Facility in Vacaville, the state Department of Corrections reported.
The Los Angeles Police Protective League, the union that represents LAPD officers, quickly issued a statement, reacting to the news.
"LAPD officers have never forgotten the horrific crime committed by Gregory Powell and Jimmy Lee Smith," wrote Tyler Izen, the president of the LAPPL. "Gregory Powell was a cold-blooded murderer who avoided the death penalty, but he won't escape God's judgement."
Powell's death comes on the heels of a memorial to the slain officer, Ian Campbell, whose name graces the Hollywood intersection where the series of events that led to his death began.
Nearly 50 years ago, Campbell and his then-partner Karl Hettinger were abducted by ex-convicts they detained in a traffic stop. The officers were taken to an onion field near Bakersfield. Campbell was fatally shot; Hettinger got away.
Campbell and Hettinger were on the beat on March 9, 1963, when they stopped ex-convicts Gregory Powell and Jimmy Lee Smith at the Hollywood intersection.
After the officers pulled them over, the men pulled out guns and abducted the officers.
Powell shot at Campbell and Hettinger in an isolated onion field near Bakersfield before he and Smith fled. Hettinger, who was not hit, fled to a nearby farmhouse where he got help.
Hettinger died in 1994.
Powell and Smith were arrested that year and eventually convicted of the crime. Over the years, Smith was paroled and repeatedly arrested by the LAPD. He died in prison serving time for a parole violation a few years ago.
State prison officials denied Powell parole 11 times. Powell failed in a final bid to be released from prison in October 2011 after pleading for compassionate release on grounds that he suffered from terminal prostate cancer.
Ten years after the killing, Joseph Wambaugh, a former LAPD sergeant, wrote the nonfiction account in a book called "The Onion Field," which also became a movie.