Sterling Hayden's character has the habit of chewing on toothpicks and at one point explains that he does this because although he loves cigarettes, his doctor says he can't have them. Hayden actually had a pack-a-day smoking habit, but director André De Toth wouldn't allow him to smoke on screen in order to get an extra level grumpiness and hostility from Hayden's performance.
'Doc' Penny:
Think about that wife of yours, Steve. You can't afford to make any mistakes.
When Gat Morgan comes to Steve and Ellen Laceys' apartment he brandishes a Smith & Wesson .38 special with a 2.5" barrel. When Steve's parole officer arrives detective Lt. Sims holds and hands the gun that Steve Lacey took from Morgan to parole officer O'Keefe. The revolver now has a 4" barrel and appears to be a Colt Police Positive.
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