He was known for surviving the "Onion Field" incident, in which he and his partner, Officer Ian Campbell, were kidnapped on the night of March 9, 1963, by criminals Gregory Powell and Jimmy Lee Smith and taken to an onion field near Bakersfield, California where Officer Campbell was fatally shot.
[10] He was married to Helen Beth Davis in Las Vegas, Nevada, on May 1, 1962; they had three children: Laurie, Kurt, and Christine.
[11] On the night of March 9, 1963, Hettinger and his partner, Ian Campbell, pulled over a vehicle driven by Powell and Smith.
The killing occurred primarily because Powell assumed that the kidnapping of the officers alone already constituted a capital crime under the Lindbergh Law.
Under the Lindbergh Law at that time, kidnapping became a capital crime only if victims were harmed or if a ransom was demanded.
"[14] In addition, Hettinger was forced to visit squad rooms and publicly admit blame for his lack of courage at the onion field.
[15] Depressed and finding it difficult to function, Hettinger was transferred to a less stressful job as a driver for the police chief.
[16] Joseph Wambaugh said of Hettinger after writing both the book and the film about the "Onion Field" incident, "Karl minded terribly, but I just exploited him.
"[21] In 1987, Hettinger was appointed by California Governor George Deukmejian to the Kern County Board of Supervisors until 1993.