... because the screenplay he penned was passable as a drama considering it was written by somebody that was not a professional writer, but mainly consisted of a lot of crime drama clichés from 1930's cinema all mixed together into a rather predictable plot.
The film has a drunken doctor (J. Carroll Naish as Dr. Morgan) with few patients who takes the easy way when he is confronted with hoodlums that are willing to pay him well to fix up members of their gang after run-ins with the law. The gang leader, Eddie Krator, is played quite convincingly by Broderick Crawford in one of his earliest screen roles. Regardless of the probable bad direction that is producing stiff performances in the rest of the cast, Crawford shines through this material and is quite good.
There are the only two significant female characters in the movie - Janice Logan representing a "good influence" in Dr. Morgan's life as Margaret Hopkins, the nurse that secretly loves him, and Heather Angel as Cynthia Weld, Morgan's socialite fiancée that seems to be more of a trophy than a love interest to him. Neither of these women gets much screen time and their performances are pretty flat.
However, there's lots of screen time for what J. Edgar knew best, the FBI agents at work and on the trail of the Krator gang and whatever doctor that has been patching them up. Here again we have a good performance by an up and coming actor - Lloyd Nolan as agent Robert Anders. As the FBI zeroes in on Krator, here we get to the few rather corny lines of the film. We are shown Krator as he knocks on door after door of his usual contacts looking for sanctuary with basically the same reply "I wouldn't help you for a million dollars! After all THESE ARE G MEN!!!!" If it comes your way I'd give it a look just to see J. Edgar Hoover doing a passable job at his writing hobby. It is certainly nothing to write home about but neither is it boring.
Interesting factoid - Broderick Crawford actually played J. Edgar Hoover in "The Private Files of J. Edgar Hoover" in 1977. Lloyd Nolan also had a part in the same film as attorney general Harlan Stone who appointed J. Edgar as head of the FBI. Members of both parties didn't like that film and nobody would have dared make it while Hoover was still alive.