His key insight is that this is not a movie about kidnapping but about the kidnappers, and especially Cesar Romero's gang leader (Tobey) and the more overtly savage Bruce Cabot character (Pitch). As far as I'm concerned, the movie is already noir, close enough, but if pre-noir fits it, that's okay too. The point is that it's ahead of its time, at least Hollywood time, and has a lot to offer.
Bruce Cabot excelled as bad guys, and another film of that time with him being a dark character is "Don't Turn "Em Loose" (1936).
The movie is mostly unsentimental. It's mostly about the gang, with a fair nod to the "Bureau of Investigation". The story doesn't show the kidnapping, the hostage, the release, or the cash turnover. It's strictly about the aftermath at the hideout. This is why it's not actually a typical gangster genre movie and far more about the 4 gang members. Dialog is hard-boiled as are situations.
George Marshall directed, not known for specializing or being a noir director; but he did do "The Blue Dahlia" and "Lust for Gold". The cinematographer is also not a noir man at the time, but is highly competent, Bert Glennon. They didn't know what noir was, as it hadn't been brought to consciousness, but they knew how to tell the story in film that fit the script. We get a no-nonsense story with occasional humor that's best described as sadistic.
I thought that I had once seen this on some noir list or other, but I do not see it at the moment, not even in Grant. That means little in terms of film enjoyment or what the film actually is or where it stands in the noir history. The newer dvd print is darker and more menacing than the older vhs prints.
The cast is strong, every one, Rochelle Hudson, Ed Norris, Ed Brophy, Warren Hymer and veteran Frank Conroy.