An exhibition to commemorate the 50th anniversary of the kidnapping of two Los Angeles Police Department officers opened Saturday at the Los Angeles Police Museum.

On March 9, 1963, Officer Ian Campbell and his partner, Karl Hettinger, pulled over two convicts for a routine traffic stop in Hollywood.

Moments later, Gregory Powell and his accomplice, Jimmy Lee Smith, pulled a gun on the officers, took them hostage and drove them out to an onion field near Bakersfield.

Campbell was executed at close range, while Hettinger was able to escape on foot.

The notorious case has been known as "The Onion Field," a reference to former LAPD Sgt. Joseph Wambaugh's 1973 book.

Glynn Martin, the executive director of the LA Police Museum, said the exhibition showcases artifacts from the case on loan from the District Attorney's Office, including the gun used to shoot Campbell and a dummy used during the trial to show how the officer was killed.

"He was murdered by a series of gunshots to his chest," said Martin.

Campbell's personal bagpipes are also on display to show how his love of the instrument has helped comfort generations after him.

"There was a bagpiper that played at his funeral...from that day forward...all the LAPD officers slain in the line of duty have had a piper," Martin said.

Also on Saturday, the LAPD and Campbell's family unveiled a model of a memorial sign for the slain officer, which stands alongside the Hollywood Freeway at the Gower overpass.

The Campbell and Hettinger families planned to meet for the first time at the exhibition's opening.