( CNN ) -- The infamous `` Onion Field '' cop killer whose 1963 crime was chronicled in a best-selling book and a movie has died , officials said Monday . He was 79 . Gregory Powell died Sunday at the California Medical Facility , a prison in Vacaville , the California Department of Corrections and Rehabilitation said in a statement . In October , Powell was denied compassionate release , all but guaranteeing he would die behind bars . He had cancer , according to the Los Angeles Police Protective League . Prison officials , however , never confirmed that account and Monday 's statement said simply that Powell died of `` natural causes . '' He was serving a life sentence with the possibility of parole for killing Los Angeles Police Officer Ian Campbell nearly 50 years ago . The crime was chronicled in Joseph Wambaugh 's best-selling book , `` The Onion Field '' and a movie by the same name . On the night of March 9 , 1963 , Powell and accomplice Jimmy Lee Smith were driving around Los Angeles , looking for a liquor store to rob . Campbell and his partner , Officer Karl Hettinger , pulled the two over in a routine stop . Powell , who was ordered out of the car , pointed a gun at Campbell 's head . He and Smith disarmed both officers , took them hostage and drove to a remote onion field in Bakersfield , a town about 110 miles of north of downtown Los Angeles . The officers were forced out of the car and ordered to stand with their hands above their heads . Powell said to them , `` We told you we were going to let you guys go , but have you ever heard of the Little Lindbergh Law ? '' `` Yes , '' Campbell , 31 , replied . Powell then shot him to death . Hettinger escaped , but the murder of his partner haunted him for the rest of his life . Powell and Smith were sentenced to death in November 1963 . Their sentences were commuted to life in prison with the possibility of parole in the early 1970s when the death penalty was declared unconstitutional . Smith was paroled in 1982 , but was in and out of prison in subsequent years for drug-related parole violations . He died at a California detention center in 2007 . The Little Lindbergh Law makes a kidnapping within the state a capital offense if the victim suffers death or other injury . Powell , however , erroneously believed the law made it a capital offense to kidnap a police officer . The Little Lindbergh Law followed a federal law , nicknamed the Lindbergh Law , that made taking a kidnapped person across state lines a federal crime . That law was passed after the kidnapping and murder of the young son of aviator Charles Lindbergh in 1932 . CNN 's Michael Martinez contributed to this report .
Joseph Wambaugh 's was 1963 . He was serving a life sentence for the 79 murder of a California police officer . The crime was chronicled in Joseph Wambaugh 's book , ` Yes , '' Campbell , 31