This is top-notch noir. The queen of the femme fatales, Gloria Grahame is perfectly cast in this sleazefest. Even the miscast Gene Barry (Bat Masterson, War of the Worlds) as a really bad guy is very good in the film as well. It was amusing to see Chuck Conners (The Rifleman, The Big Country) as a cop; a role he was well-suited for. He was a much better actor than baseball player.
The story is pretty good with one exception; why would you hold on to a gun that killed a cop if you were wealthy? The escalation of violence and the gruff Sterling Hayden (perfectly cast) harassing the suspect from the beginning of the film without let-up is perfectly logical, although not legally sound. The film is in the top echelon of this genre; don't miss it.