
Alexander Harper Berkeley (born December 16, 1955) is an American actor. He is known for his television roles as Sheriff Thomas McAllister on the crime drama The Mentalist, George Mason on the political thriller series 24, Percy Rose on the action thriller series Nikita, the Man on The Booth At The End and Gregory in AMC's The Walking Dead. His notable film roles include Todd Voight in Terminator 2: Judgment Day, Agent Gibbs in Air Force One, Bowery Snax in Sid and Nancy, Dr. Lamar in Gattaca, Trevor Lyle in Candyman and Ralph in Heat.

Heat
1995 · as Ralph

Terminator 2: Judgment Day
1991 · as Todd Voight

Fracture
2007 · as Judge Moran

The Rock
1996 · as Lonner (uncredited)

Apollo 13
1995 · as Henry Hurt

Faster
2010 · as Sergeant Mallory

Taken
2008 · as Stuart St. John

A Few Good Men
1992 · as Capt. Whitaker

Kick-Ass
2010 · as Detective Gigante

Air Force One
1997 · as Agent Gibbs

Gattaca
1997 · as Dr. Lamar

Candyman
1992 · as Trevor Lyle

Shanghai Noon
2000 · as Nathan Van Cleef

Allegiant
2016 · as Phillip

Transcendence
2014 · as Dr. Thomas Casey

Leaving Las Vegas
1995 · as Cynical Cabbie

Solace
2015 · as Mr. Ellis

Son of Batman
2014 · as Dr. Kirk Langstrom (voice)