'Onion Field' killer loses 11th parole bid

LOS ANGELES, Jan. 28 (UPI) -- The 1963 killer of a Los Angeles police officer, the basis for Joseph Wambaugh's novel "The Onion Field," has lost his 11th parole bid, authorities said.

Gregory Powell originally drew the death penalty but his sentence eventually was commuted to life with possibility of parole. He will be eligible for another try in three years, the Los Angeles Times reported.

Powell was convicted of killing police officer Ian Campbell in an onion field near Bakersfield, Calif. Another officer, Karl Hettinger, escaped. Powell's partner died in prison.