HOLLYWOOD (CBSLA.com) — A new freeway sign paying tribute to an officer killed in a crime that came to be known as “The Onion Field” murder was unveiled on Saturday.

Officer Ian Campbell and his partner, Karl Hettinger, were kidnapped 50 years ago not far from the Gower overpass alongside the Hollywood Freeway where the new sign stands.

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They were taken to an onion field in Kern County where Campbell was executed at close range.

LAPD Chief Charlie Beck said he hopes the memorial sign serves as a reminder of the sacrifices that police officers have made.

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“Since that day in 1963, 84 other Los Angeles police officers have lost their lives in the line of duty. Two-hundred and four Los Angeles police officers in total have given their lives for the city of Los Angeles,” Beck said. “People should remember that sacrifice.”

Also on Saturday, an exhibition about the crime opened at the Los Angeles Police Museum in Eagle Rock.

The kidnappings and murder became the basis of a best-selling book and film.

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