Orange County Sheriff's Department, California
End of Watch Monday, October 24, 1988
Add to My HeroesMark Steven Tonkin
Deputy Sheriff Mark Tonkin was killed in a helicopter accident while working on a multi-agency narcotics task force along the United States border.
A suspicious vehicle was spotted in a canyon on a remote access road in the Mountain Springs Grade area. The UH-1H helicopter began to descend when its rotor blades struck power lines and caused it to crash in the foothills of the Laguna Mountains.
Also killed in the accident were Investigator Michael Davis of the Riverside County Sheriff's Department, Deputy Roy Chester of the Los Angeles County Sheriff's Department, Sergeant Richard Romero of the Imperial County Sheriff's Department, Deputy Mark Tonkin of the Orange County Sheriff's Department, and the three California National Guard crew members operating the flight.
Deputy Tonkin had served with the Orange County Sheriff's Department for seven years. He was survived by his wife and parents.
Bio
- Age 31
- Tour 7 years
- Badge Not available
Incident Details
- Cause Aircraft accident
Most Recent Reflection
View all 17 ReflectionsMark - I think of you always; with respect, admiration, and love. Rest in peace.
“Kitty”
May 14, 2023
Recent LODD Deaths

Police Officer Jeremy R. Labonte
Roswell Police Department, GA
EOW: February 7, 2025

Officer Jason Roscow
North Las Vegas Police Department, NV
EOW: February 4, 2025

Major Jeffrey A. Burke
New Jersey State Police, NJ
EOW: December 31, 2024

Corporal Dennis Francis Kelly
Delaware State Police, DE
EOW: December 21, 2024

Officer Baldino Morales-Sánchez
Mayagüez Municipal Police Department, PR
EOW: January 25, 2025

Border Patrol Agent David Christopher Maland
United States Department of Homeland Security - Customs and Border Protection - United States Border Patrol, US
EOW: January 20, 2025

Sergeant Mark Butler
Navasota Police Department, TX
EOW: January 15, 2025

Deputy Sheriff Jesus Vargas
Brazoria County Sheriff's Office, TX
EOW: January 15, 2025

Police Officer II Colton Dale Pulsipher
Las Vegas Metropolitan Police Department, NV
EOW: December 12, 2024