Mr. Prosky — who was perhaps best known for his stint as old-school cop Stanislaus "Stan" Jablonski on TV's "Hill Street Blues," and for supporting turns in films such as "Broadcast News" and "Outrageous Fortune" — began his acting career at Washington's Arena Stage. There when the regional theatre movement in the U.S. was aborning, he essayed 130 roles over 23 seasons at the Arena, including Willy Loman in Death of a Salesman and the title role in Brecht's Galileo, and worked with the likes of Jane Alexander, Robert Foxworth and James Earl Jones. His final appearances at the Arena included revivals of Awake and Sing! (2006) and Noises Off (2007).

He played a half-dozen roles on Broadway, the most famous being the desperate salesman Shelly "The Machine" Levine in David Mamet's terse drama Glengarry Glen Ross (1984), and a wily Soviet diplomat sparring with American negotiator Sam Waterston in Lee Blessing's A Walk in the Woods (1988). He was nominated for a Tony Award for both parts.

Mr. Prosky made his Broadway debut in Michael Weller's Moonchildren in 1972. He was Alfieri in a 1984 revival of Arthur Miller's A View From the Bridge. More recently, he took a role as a German politician in Michael Frayn's Democracy in 2004, and was a willful rabbi in an Off-Broadway revival of the Yiddish drama The Golem in 2002. He acted in Miller's The Price earlier this year at the Walnut Street Theatre.

	Robert Prosky in Democracy
	photo by Don Perdue

He was best suited to playing salt-of-the-earth characters, sometimes with a mischievous or slightly sinister edge. He portrayed a defense lawyer in "Dead Man Walking" and was a corrupt judge, holding back ballplayer Robert Redford in "The Natural." Other films in which he played key roles include "Mrs. Doubtfire," "Last Action Hero," "Hoffa," "Far and Away" and "Mad City." Mr. Prosky was offered both the role of the Coach on the sitcom "Cheers" and the part of Frasier Crane's father on its spin-off "Frasier." But he expressed no regret as passing up the gigs on the long-running shows. "Doing the same role for 6 1/2 years" sent a chill down his spine, he said. Robert Porzuczek was born Dec. 13, 1930, in Philadelphia, PA, to Polish-American parents. He began his professional career as a grocer in his hometown of Manayunk.

Mr. Prosky's name rarely appeared in the papers outside of the reviews of his films and stage roles. An exception came in 2003, when he wrote an angry letter to the editor of the Washington Post, complaining about Post drama critic Peter Marks. "I have returned from films and Broadway to do what I believe to have been two very good plays that were beautifully produced at Arena," he wrote. "Theater in Washington has advanced greatly both in quantity and above all in artistic quality since my first days at Arena. Unfortunately, the same cannot be said for your paper's theater critic."

He is survived by his wife of 48 years, Ida Hove, and three children, including Stefan, and actors Andy Prosky and John Prosky.