Richard Allen Dysart ( March 30 , 1929 -- April 5 , 2015 ) was an American actor , perhaps best known for his role as Leland McKenzie on the NBC legal drama `` L.A. Law '' .
Richard A. Dysart ( March 30 , 1929 -- April 5 , 2015 ) was an American actor . He was best known for his role as Leland McKenzie on the NBC legal drama `` L.A. Law '' .