The cause was complications of leukemia, said a representative, Dominic Mancini.
In a more than half-century career as a Hollywood role player, Mr. Wilson was best known for playing villains and rogues, often with a Southern accent that he drew from his upbringing in small-town Georgia.
He shot Robert Redford’s title character to death in the 1974 adaptation of ‘‘The Great Gatsby”; played a dog-hating, squirrel-killing neighbor in the family film ‘‘Shiloh’’ (1997) and its two sequels; and received a Golden Globe nomination as Captain Billy Cutshaw, a psychologically troubled former astronaut, in ‘‘The Ninth Configuration’’ (1980), written and directed by ‘‘Exorcist’’ novelist William Peter Blatty.
But Mr. Wilson said he often struggled to find original, interesting work as an actor, and battled with studio executives who typecast him in parts similar to Dick Hickock, the tousle-haired young killer he portrayed in ‘‘In Cold Blood.’’ Supporting himself as a commercial painter, he sometimes went years without acting, leading film critic Glenn Lovell to describe him in 1996 as ‘‘one of Hollywood’s most respected but least utilized character actors.’’
His reputation rested largely on his first two movies, a pair of 1967 crime dramas that launched him from jobs as a valet and oil company clerk to national renown. Mr. Wilson played murder suspect Harvey Oberst in director Norman Jewison’s ‘‘In the Heat of the Night,’’ based on a novel by John Ball about a black police detective from Philadelphia (Sidney Poitier) who investigates a murder in Mississippi. The movie won five Academy Awards, including the Oscar for best picture.
Four months after its release, Mr. Wilson appeared as one of the two leads in ‘‘In Cold Blood,’’ based on Truman Capote’s account of a quadruple murder in rural Kansas. The killings — committed by Hickock and a fellow drifter, Perry Smith — became a national sensation after they were chronicled by Capote, whose ‘‘nonfiction novel’’ detailed the lead-up to the crimes, the killers’ arrests, and their executions in 1965.
The film was written and directed by Richard Brooks, who cast Mr. Wilson and his on-screen partner, Robert Blake, in large part because of their resemblance to Hickock and Smith. Aiming to give the movie a documentary-like feel, Brooks shot in black-and-white and on location, filming the murder scenes in the farmhouse where Herbert Clutter and his family were robbed and then killed. Seven of the case’s original jurors appeared in the film’s trial scenes.
‘‘To the degree that ‘In Cold Blood’ is an accurate, sensitive record of actual events, it succeeds overpoweringly,’’ wrote movie critic Roger Ebert. Mr. Wilson and Blake, he added, ‘‘are so good they pass beyond performances and almost into life.’’
‘‘Every actor in the English-speaking world wanted those two roles, including [Paul] Newman and [Steve] McQueen,’’ Mr. Wilson told Lovell. ‘‘Brooks hired two ‘unknowns’ and he wanted to keep it that way. We were treated like two killers he had somehow run across.’’ When the performers appeared alongside Capote on the cover of Life magazine, they were described only as ‘‘actors playing killers,’’ without giving their names.
Mr. Wilson experienced a late-career resurgence with ‘‘The Walking Dead’’ on AMC, playing farmer and veterinarian Hershel Greene from 2011 to 2014. His character lost a leg in season three before losing his head in season four. But shortly before Mr. Wilson’s death was announced Saturday, a ‘‘Walking Dead’’ panel at New York Comic Con confirmed that he would appear in the show’s ninth season. According to Variety, Mr. Wilson had already filmed his scenes.
William Delano Wilson was born in Atlanta. His father was a building contractor who died when Mr. Wilson was 12, leading his mother to move the family to her hometown of Thomasville, near the Florida border.
Mr. Wilson graduated from high school there in 1960 and received a basketball scholarship to what was then Southern Polytechnic State University in Chamblee, Ga., where he studied architecture before dropping out, hitchhiking to California, and enrolling in acting classes. He spent several years performing in local theater productions before landing an audition for ‘‘In the Heat of the Night’’ with the help of a friend’s stepfather, a casting director.
Mr. Wilson’s early work also included the 1969 movies ‘‘Castle Keep’’ and ‘‘The Gypsy Moths,’’ both starring Burt Lancaster, and ‘‘The New Centurions,’’ a police drama directed by Richard Fleischer. He was test pilot Scott Crossfield in ‘‘The Right Stuff’’ (1983), based on Tom Wolfe’s book about the space program, and — in a rare leading role — appeared as a love-struck World War II soldier in ‘‘A Year of the Quiet Sun’’ (1984).
The latter was directed by Polish filmmaker Krzysztof Zanussi, with whom Mr. Wilson reunited for ‘‘Our God’s Brother’’ (1997), playing Saint Albert Chmielowski. He recalled being praised for reaching ‘‘deeply into the character’’ by Pope John Paul II, who had written the play on which the movie was based.
Mr. Wilson appeared to have broken out of a professional slump with his performance as a prison chaplain in ‘‘Dead Man Walking’’ (1995), and in recent years was credited in movies that included ‘‘Pearl Harbor’’ (2001), and ‘‘Monster’’ (2003). He also played the casino-boss father of actress Marg Helgenberger in the television series ‘‘CSI: Crime Scene Investigation.’’
He married Heavenly Koh, a lawyer, artist, and his only immediate survivor, in 1977.