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.
as Fred O'Brien
as Harris
as Self
as George Schultz
as Maynard
as Gilad Pellaeon (voice)
as Gordon
as Charlie Hoge
as Joel
as Michael Rand
as Priest
as Mario Castelnuovo-Tedesco
as Self - Guest
as Maurice Hewitt
as Priest James
as Lee Hackman
as Gilad Pellaeon
as Edwards
as Uncle
as Dr. Roberts
as Mr. Milk
as Artemis
as Phillip
as General John Acosta
as Judge Hollingsworth
as Mr. Ellis
as Forrest Bobo
as Peter Lockwood
as Ronnie 'Dogstick' Brannigan
as Jonathan Foster
as Dr. Kirk Langstrom (voice)
as Frank Devore
as Chick
as Dr. Thomas Casey
as Uncle Jeff
as Magistrat Hale
as Kenneth
as Dr. Lansen
as Manhunter / Paul Kirk (voice)
as Jeremiah Rains
as Peter
as Lieutenant Durgan
as Moe
as The Man
as Liam McClean
as Liam McLean
as Detective Carter
as Sergeant Mallory
as McMahon
as Detective Gigante
as Harry
as Gregory
as Percy Rose
as Warden Morgg / Trukk (voice)
as Charles Monroe
as Mr. Frost
as Captain Atom (voice)
as Father De La Chasse
as King
as Sonny
as Dad
as Sid Harris
as Stuart St. John
as Sinestro (voice)
as Sheriff Thomas McAllister
as Judge Moran
as Railroad Foreman
as Uncle Doug
as Peter Shepherd
as John Smith (uncredited)
as John Smith (voice)
as Gus
as Harkness
as Arlen Pavich
as Jonathan
as Det. Hyde
as Dr. Bancroft
as Detective Curt Landry
as Mitchell Slocombe
as Admiral Kentz
as Self
as A.D.A. Rex Swarthmore
as Paul (voice)
as Tommy Tulip
as Joey Patterson
as Mento / General Immortus (voice)
as Warp (voice)
as Harry Kellogg
as Mr. DeMarco
as Virgil Koster
as Dakar Johnston
as General Brak / Dignitary / Soldier (voice)
as General Brak / Soldier (voice)
as George Mason
as George Pagolis
as Carl
as Clay Shelton
as Nathan Van Cleef
as Evan Wantz
as Rory Atwater
as Dr. Dylan Cotner
as Bo Tyler
as Yepihodov
as Franklin Hollis
as Bo Tyler
as Dr. Childes (voice)
as Gavreau
as Lt. Clyde Webber
as J.D. Johnson
as George
as Barking Deer #2 (voice)
as Stoat (voice)
as Male Interviewer
as Hammond
as Dr. Lamar
as Secret Service Agent Gibbs
as Danny “Figaretto” Evans
as Additional Voices (voice)
as Tosh
as Buzz Aldrin
as Date #4 (uncredited)
as John Barrows
as Gentry
as Ryan
as Lonner (uncredited)
as Alexander Willis
as Sunburned Man
as Donald Falk
as Sgt. Corey Mills (voice)
as Jimbo
as Neil Wojak
as Ralph
as Cynical Cabbie
as Henry Hurt
as Greg
as Shakespeare
as Terry McCammon
as Second Man
as Sherman Carson
as Joey Szabo
as Detective Wilson
as Octopaganini (voice)
as Russ Loring
as James Blakemore
as Dr. Hodge
as Brett Bones
as Bernard
as Capt. Whitaker
as Kozolowski
as Trevor Lyle
as Marchat
as Peter Zenner
as Harold
as Roberts, Vietnam
as Harvey Preston
as Todd Voight
as Wayne
as Bruce MacNamara
as Harry Copeland
as Blackwell
as Lt. Pierson
as Stark
as Detective
as Fast Eddie
as John Patrick Earl
as Monty Griswold
as Rudy Mohr
as Clay Pollack
as Jeffrey
as Lloyd
as Waingro
as Jack Torme
as Ricky Fell
as Cardogan
as Ez Andy
as Byron Cole
as Preacher McMahon
as Yo-Yo
as Bowery Snax
as Kent Sutcliffe
as Scalper
as Baker
as Sergeant Wilson
as Connally
as Dan Kowalski
as Christopher Crawford
as Buzz Whitehead
as Marine
as Producer