The two officers were then forced into Powell's car and, within 30 seconds after the traffic stop began, were driven north from Los Angeles on Route 99, to an onion field near Bakersfield, where Campbell was fatally shot.

[3] The killing occurred primarily because Powell assumed that the kidnapping of the officers alone already constituted a capital crime under the state's Little Lindbergh Law.

"[4][5] Although Hettinger escaped, he felt scorned by his fellow officers and officials at the Los Angeles Police Department,[6] and suffered severe emotional trauma for both the initial incident and the following treatment.

[7] Powell was arrested on the night of the murder, after being spotted driving a stolen vehicle by California Highway Patrol officers.

With Valerie Campbell's help, he collected 31,500 signatures in three and a half weeks, which were submitted to the California Board of Prison Terms, along with several thousand letters.

Valerie Campbell then joined Citizens for Truth's representatives, John Mancino and Dr. Howard Garber, along with the group's attorneys, in filing a legal brief in the First District Court of Appeals in San Francisco, demanding that Powell remain in prison.

In a January 21, 2010 letter to state corrections officials, Los Angeles Police Union President Paul Weber urged the board to deny parole, calling Powell a "vicious murderer who has not yet paid his debt to society".

[9] On October 18, 2011, the California State Parole Board denied compassionate release for Powell, who had been diagnosed with terminal prostate cancer.

It starred John Savage as Karl Hettinger, James Woods as Gregory Powell, Franklyn Seales as Jimmy Smith, and Ted Danson (in his film debut) as Ian Campbell.

[13] TNT's Southland season 5 episode 9 titled "Chaos" (original airdate April 10, 2013) portrayed a reimagined version of the events that took place in The Onion Field.