Deputy Mark Tonkin, an eight-year veteran of the Sheriff-Coroner Department, lost his life in an evening helicopter crash on October 24, 1988. It happened while he was assigned to Operation Border Ranger, a multi-agency cooperative narcotic enforcement program. Mark was one of eight victims aboard a California National Guard UH-1H Huey Helicopter when it went down and burned in mountainous terrain near El Centro, California.

The other members of the narcotic team on that ill-fated mission were two deputies from the Los Angeles County Sheriff’s Department, one deputy from Riverside County Sheriff, one from the Imperial County Sheriff’s Office, and three officers from the California National Guard. Over the years, Operation Border Ranger has involved personnel from the Drug Enforcement Administration, U.S. Customs, Border Patrol, San Bernardino County Sheriff, and San Diego County Sheriff.

Deputy Tonkin joined the Department on August 21, 1981. He was initially assigned to the Main Jail upon completing basic training. He worked a short time as a court bailiff and then was assigned to North Patrol. In January of 1988, Deputy Tonkin joined the Career Criminal Apprehension Team.

Deputy Tonkin was survived by his wife, Mary Ann, and parents, James and Gloria Tonkin of Whittier.