Biography
Richard Allen Dysart (March 30, 1929 – April 5, 2015) was an American actor. He is best known for his role as senior partner Leland McKenzie in the television series L.A. Law (1986–1994), for which he won a 1992 Primetime Emmy Award as Outstanding Supporting Actor in a Drama Series after four consecutive nominations. In film, he held supporting roles in The Hospital (1971), Being There (1979), The Thing (1982), Mask (1985), Pale Rider (1985) and Wall Street (1987).
Description above from the Wikipedia article Richard Dysart, licensed under CC-BY-SA, full list of contributors on Wikipedia.
Filmography
Cast Credits

Everything Is Terrible! The Movie
Character: Self (archive footage)
MOVIE • 2009

Proteus: A Nineteenth Century Vision
Character: The Ancient Mariner (voice)
MOVIE • 2004

L.A. Law: The Movie
Character: Leland McKenzie
MOVIE • 2002

Todd McFarlane's Spawn 2
Character: Cogliostro
MOVIE • 1998

Hard Rain
Character: Henry Sears
MOVIE • 1998

Spawn
Character: Nicholas Cogliostro (voice)
TV • 1997

E! True Hollywood Story
Character:
TV • 1996
Corwin
Character: Self
MOVIE • 1996

A Child Is Missing
Character: Riley Hallihan
MOVIE • 1995

Truman
Character: Henry L. Stimson
MOVIE • 1995

Panther
Character: J. Edgar Hoover
MOVIE • 1995
Marilyn & Bobby: Her Final Affair
Character: J. Edgar Hoover
MOVIE • 1993

Batman: The Animated Series
Character: Dr. Bartholomew (voice)
TV • 1992

Back to the Future Part III
Character: Barbwire Salesman
MOVIE • 1990

Day One
Character: President Harry S. Truman
MOVIE • 1989

Mickey's 60th Birthday
Character: Leland McKenzie
MOVIE • 1988

Moving Target
Character: Arthur Cambridge
MOVIE • 1988

Your Alcohol I.Q.
Character: Self
MOVIE • 1988

Wall Street
Character: Cromwell
MOVIE • 1987

Jay Leno's Family Comedy Hour
Character: Self
MOVIE • 1987