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.
No Address
Harris
2025
Americans with No Address
Self
2024
The Ghost Trap
Maynard
2024
Heightened
Gordon
2023
Butcher's Crossing
Charlie Hoge
2023
The Audition
Joel
2022
Alchemy of the Spirit
Oliver
2022
The Wall of Mexico
Michael Rand
2020
The Maestro
Mario Castelnuovo-Tedesco
2018
City of Lies
Edwards
2018
Proud Mary
Uncle
2018
Shot
Dr. Roberts
2017
Born Guilty
Mr. Milk
2017
Moments of Clarity
Artemis
2016
Allegiant
Phillip
2016
Solace
Mr. Ellis
2015
The Gift
Forrest Bobo
2015
Son of Batman
Dr. Kirk Langstrom (voice)
2014
This Last Lonely Place
Frank Devore
2014
Small Time
Chick
2014
Transcendence
Dr. Thomas Casey
2014
Pony
Uncle Jeff
2014
Live at the Foxes Den
Kenneth
2013
Louder Than Words
Dr. Lansen
2013
That Guy... Who Was in That Thing
Self
2012
Tales of Everyday Magic
Peter Keller
2012
Five
Peter
2011
Seeking Justice
Lieutenant Durgan
2011
Girl Walks Into a Bar
Moe
2011
Luster
Detective Carter
2010
Below the Beltway
McMahon
2010
Kick-Ass
Detective Gigante
2010
Bedrooms
Harry
2010
Superman/Batman: Public Enemies
Captain Atom (voice)
2009
Repo Chick
Father De La Chasse
2009
Year One
King
2009
Cook County
Sonny
2009
The Toe Tactic
Dad
2009
Taken
Stuart St. John
2008
Fracture
Judge Moran
2007
Seraphim Falls
Railroad Foreman
2007
The Garage
Doc Ruppert
2006
Out There
Uncle Doug
2006
Magma: Volcanic Disaster
Peter Shepherd
2006
Deepwater
Gus
2005
Drop Dead Sexy
Harkness
2005
Standing Still
Jonathan
2005
In Enemy Hands
Admiral Kentz
2004
The Third Date
Tommy Tulip
2003
Quicksand
Joey Patterson
2003
Storytelling
Mr. DeMarco
2001
China: The Panda Adventure
Dakar Johnston
2001
Shanghai Noon
Nathan Van Cleef
2000
Timecode
Evan Wantz
2000
Universal Soldier: The Return
Dr. Dylan Cotner
1999
NetForce
Bo Tyler
1999
The Cherry Orchard
Yepihodov
1999
Winchell
Gavreau
1998
Phoenix
Lt. Clyde Webber
1998
The Truth About Juliet
George
1998
Breast Men
Male Interviewer
1997
Amistad
Hammond
1997
Gattaca
Dr. Lamar
1997
Air Force One
Agent Gibbs
1997
Persons Unknown
Tosh
1996
Apollo 11: First Steps on the Moon
Buzz Aldrin
1996
If These Walls Could Talk
John Barrows
1996
Within the Rock
Ryan
1996
The Rock
Lonner (uncredited)
1996
Barb Wire
Alexander Willis
1996
Poison Ivy 2: Lily
Donald Falk
1996
A Kidnapping in the Family
Curtis Harrison
1996
Heat
Ralph
1995
Leaving Las Vegas
Cynical Cabbie
1995
Apollo 13
Henry Hurt
1995
Safe
Greg
1995
Attack of the 50 Ft. Woman
Second Man
1994
Roswell
Sherman Carson
1994
Caroline at Midnight
Joey Szabo
1994
Donato and Daughter
Russ Loring
1993
It's Nothing Personal
James Blakemore
1993
A Few Good Men
Capt. Whitaker
1992
Deadly Matrimony
Kozolowski
1992
Candyman
Trevor Lyle
1992
A Private Matter
Peter Zenner
1992
The Keys
Harold
1992
Terminator 2: Judgment Day
Todd Voight
1991
Murder in High Places
Wayne
1991
Not of This World
Bruce MacNamara
1991
Dillinger
Harry Copeland
1991
The Rookie
Blackwell
1990
The Grifters
Lt. Pierson
1990
Short Time
Stark
1990
The Guardian
Detective
1990
The Gumshoe Kid
Monty Griswold
1990
The Fabulous Baker Boys
Lloyd
1989
L.A. Takedown
Waingro
1989
Deadly Dreams
Jack Torme
1988
The Verne Miller Story
Cardogan
1988
The Lawless Land
Ez Andy
1988
Walker
Byron Cole
1987
Straight to Hell
Preacher McMahon
1987
Omega Syndrome
Yo-Yo
1986
Sid and Nancy
Bowery Snax
1986
Volunteers
Kent Sutcliffe
1985
Inside the Box
Fred O'Brien
Rust
Blackburn
2025
Reagan
George Schultz
2024
Star Wars: Tales of the Empire
Gilad Pellaeon (voice) · (1 episode)
2024
Dead Talk Live
Self - Guest · (1 episode)
2020
The Dark and the Wicked
Priest
2020
FBI: Most Wanted
Maurice Hewitt · (1 episode)
2020
Truth Be Told
Lee Hackman · (7 episodes)
2019
The Mandalorian
Gilad Pellaeon · (1 episode)
2019
Dark Harbor
Priest James
2019
MacGyver
General John Acosta · (1 episode)
2016
Bull
Judge Hollingsworth · (1 episode)
2016
Supergirl
Peter Lockwood · (1 episode)
2015
Zoo
Ronnie 'Dogstick' Brannigan · (4 episodes)
2015
12 Monkeys
Jonathan Foster · (3 episodes)
2015
Salem
Magistrat Hale · (13 episodes)
2014
Beware the Batman
Manhunter / Paul Kirk (voice) · (1 episode)
2013
Longmire
Jeremiah Rains · (2 episodes)
2012
The Booth at the End
The Man · (10 episodes)
2011
Being Human
Liam McClean · (5 episodes)
2011
Being Human
Liam McLean · (3 episodes)
2011
Faster
Sergeant Mallory
2010
The Walking Dead
Gregory · (15 episodes)
2010
Nikita
Percy Rose · (45 episodes)
2010
Ben 10: Ultimate Alien
Warden Morgg / Trukk (voice) · (1 episode)
2010
Justified
Charles Monroe · (2 episodes)
2010
Women in Trouble
Mr. Frost
2009
Sparks
Sid Harris
2009
Batman: The Brave and the Bold
Sinestro (voice) · (1 episode)
2008
The Mentalist
Sheriff Thomas McAllister · (5 episodes)
2008
Jericho
John Smith (uncredited) · (1 episode)
2006
Jericho
John Smith (voice) · (1 episode)
2006
Criminal Minds
Det. Hyde · (1 episode)
2005
Bones
Dr. Bancroft · (1 episode)
2005
The Closer
Detective Curt Landry · (1 episode)
2005
North Country
Arlen Pavich
2005
Medium
Mitchell Slocombe · (1 episode)
2005
100 Scariest Movie Moments
Self · (5 episodes)
2004
Boston Legal
A.D.A. Rex Swarthmore · (1 episode)
2004
The Batman
Paul (voice) · (1 episode)
2004
The Last Full Measure
2004
Karen Sisco
Alvin Simmons · (1 episode)
2003
Teen Titans
Mento / General Immortus (voice) · (2 episodes)
2003
Teen Titans
Warp (voice) · (1 episode)
2003
The Twilight Zone
Harry Kellogg · (1 episode)
2002
The Court
Keith Nolan · (3 episodes)
2002
Justice League
General Brak / Soldier (voice) · (1 episode)
2001
Justice League
General Brak / Dignitary / Soldier (voice) · (1 episode)
2001
24
George Mason · (27 episodes)
2001
Law & Order: Criminal Intent
George Pagolis · (1 episode)
2001
The Man from Elysian Fields
Virgil Koster
2001
Going to California
Clay Shelton · (1 episode)
2001
CSI: Crime Scene Investigation
Rory Atwater · (5 episodes)
2000
The West Wing
Franklin Hollis · (1 episode)
1999
Netforce
Bo Tyler · (2 episodes)
1999
Batman Beyond
Dr. Childes (voice) · (2 episodes)
1999
The Wild Thornberrys
Barking Deer #2 (voice) · (1 episode)
1998
The Wild Thornberrys
Stoat (voice) · (1 episode)
1998
Driven
J.D. Johnson
1998
The Legend of Calamity Jane
Additional Voices (voice) · (1 episode)
1997
Extreme Ghostbusters
(1 episode)
1997
The Killing Jar
Danny “Figaretto” Evans
1997
For Hope
Date #4 (uncredited)
1996
Bulletproof
Gentry
1996
Superman: The Animated Series
Sgt. Corey Mills (voice) · (1 episode)
1996
Women: Stories of Passion
Jimbo · (1 episode)
1996
A Family Thing
Sunburned Man
1996
Nash Bridges
Neil Wojak · (1 episode)
1996
Partners
Christophe Nnngaarzh · (1 episode)
1995
The Outer Limits
Terry McCammon · (1 episode)
1995
The Fifteen Minute Hamlet
Shakespeare
1995
Life with Louie
Pro Shop Cashier (voice) · (1 episode)
1994
Gargoyles
Iago (Voice) · (1 episode)
1994
ER
Detective Wilson · (1 episode)
1994
New York Undercover
Dr Carl Weschler · (1 episode)
1994
Duckman
Hans (voice) · (1 episode)
1994
The X-Files
Dr. Hodge · (1 episode)
1993
The Adventures of Brisco County, Jr.
Brett Bones · (1 episode)
1993
Good Advice
Bernard · (1 episode)
1993
The Gun in Betty Lou's Handbag
Marchat
1992
For the Boys
Roberts, Vietnam
1991
Billy Bathgate
Harvey Preston
1991
Law & Order
Clay Pollack · (1 episode)
1990
The Last of the Finest
Fast Eddie
1990
The Assassin
John Patrick Earl
1990
Internal Affairs
Rudy Mohr
1990
Tapeheads
Ricky Fell
1988
Wiseguy
Ray Spiotta · (1 episode)
1987
The Twilight Zone
(segment "Take My Life...Please!") · (1 episode)
1985
Moonlighting
Scalper · (1 episode)
1985
Miami Vice
Tommy Lowell · (2 episodes)
1984
The A-Team
Baker · (1 episode)
1983
Remington Steele
Dan Kowalski · (1 episode)
1982
Fire on the Mountain
1981
Oddities
Tales of the Gold Monkey
Eric Fromby · (1 episode)
1982
Cagney & Lacey
Maurice · (1 episode)
1982
Falcon Crest
Buzz Whitehead · (1 episode)
1981
Hart to Hart
Christopher Hawks · (1 episode)
1979
The Incredible Hulk
Tom · (1 episode)
1977
M*A*S*H
Marine · (1 episode)
1972
Day One
(1 episode)
Gargoyles
Coldsteel (Voice) · (1 episode)
1994
The Tick
Octopaganini (voice) · (1 episode)
1994
Super Force
Dr Landru · (3 episodes)
1990
Grand
Jeffrey · (1 episode)
1990
Riptide
Taxi Driver · (1 episode)
1984
The A-Team
Sergeant Wilson · (1 episode)
1983
Tag: The Assassination Game
Connally
1982
Mommie Dearest
Christopher Crawford
1981