Dennis Farina, the actor and former Chicago police officer who played coiled, hot-tempered characters in movies and on television, died Monday in Scottsdale, Ariz., from a blood clot in his lung, his publicist said. He was 69.

Plenty of actors invest time doing research for their roles, but most of them had nothing on Dennis Farina. Farina spent nearly two decades as a Chicago cop, a career that led him to work as a consultant for director Michael Mann. Mann saw something in the raspy-voiced burglary cop, giving him a small part in his movie Thief in 1981, then casting him as star of his hard-boiled TV drama Crime Story.

Farina was best known for his role as Det Joe Fontana on New York-based police show Law and Order.

"I was stunned and saddened to hear about Dennis' unexpected passing this morning," Law & Order creator Dick Wolf said in a statement on Monday. "The Law & Order family extends sympathy and condolences to his family. He was a great guy."