The burglary tools used throughout the film (such as the hydraulic drill used in the opening sequence) were not props, but real tools which the actors were trained to use. The tools were supplied by real-life thieves who served as technical consultants on the film, principally John Santucci, who also portrayed Sergeant Urizzi on-screen.
The vault, into which which Frank breaks, in the opening scene, was a real vault, purchased at a cost of ten thousand dollars, specifically so that James Caan could break into it, using the tools and techniques supplied by John Santucci.
The house that was "severely damaged" in the explosion was demolished, and three smaller houses were built on the property. Apparently, the explosive charge was too large for the job, as it caused a fire, and cracked the house's foundation.
According to James Caan on the DVD commentary, Frank is based on John Santucci. But Caan avoided doing an impersonation of Santucci's exuberant personality, because he felt that it would seem too comedic.
DIRECTOR_TRADEMARK(Michael Mann): [Cops & Robbers]: Many real-life Chicago criminals and police officers served as advisors to Director Michael Mann, and Mann cast many of them on-screen, often in contradictory roles (former Chicago police officers Dennis Farina and Nick Nickeas appear as criminal henchmen, while former professional thief John Santucci appears as a police officer).
When Frank tries to light his cigarette in the diner scene, the lighter does not work. This was not scripted. The prison story that Frank tells in his monologue is based on a letter Michael Mann received from a real inmate.
Dennis Farina was a Chicago policeman at the time of filming. He played a henchman. Conversley, John Santucci, who played a corrupt cop, was a recently paroled thief, and was a Technical Advisor. They were cast in Michael Mann's television series Crime Story (1986), Farina as Chicago police Lieutenant Colonel Joshua Tree, and Santucci as a jewel thief. William Petersen, who appeared (along with Farina) in Mann's Manhunter (1986), appears briefly as a bouncer at a club.
James Caan went to Gunsite (then known as the American Pistol Institute) in Paulden, AZ to learn proper gun handling. It's owner, retired Marine Lt. Col. Jeff Cooper did not hold the belief that a professional thief would take the time and discipline to learn to use firearms, clear rooms and properly handle weapons. He had his chief instructor, Chuck Taylor teach him as much as he could in 3 days. The training stuck and Caan has shown similar gun handling in Alien Nation and The Way Of The Gun.
The Green Mill is a Jazz club and cocktail lounge in uptown Chicago at Lawrence and Broadway. It was a favorite hangout for Al Capone and his henchmen. There are several historic items on the walls and a particular booth that Capone preferred because it allows a clear view of the front AND rear doors, thus making it difficult for anyone to sneak up on him and his associates while they were doing business. Truly a classic Chicago icon, the Green Mill is worth a visit!
The house that was blown up was actually a fake structure in front of the real house; nevertheless, when it blew up it heavily damaged the real house behind it. The residents and neighbors were moved to a hotel during filming.