B-movies in the 1930s and 40s were inexpensively made and relatively short films that were shown as part of a double-feature. Many were made by "poverty row" studios--tiny independent companies that often rented space on the major studio lots at night. For the most part, Bs are entertaining enough, but also tend to have lesser actors, writers and directors--sort of like the minor leagues for movie people. Because of this, most B-films are not the quality or entertainment level of an A-picture--though there are many, many exceptions. As For me, I often prefer the Bs--they can be fun, entertaining and usually very fast-moving--as a typical B is about 60 minutes (more or less).
The film starts with a relatively dumb ex-college football star getting out of prison after serving three years for a robbery. Dave continues to deny that he did anything wrong and vows to look up all the witnesses who testified against him and make them tell the truth. However, he needs to be careful, as he is on parole--one slip and he's back in the can. Interestingly, all but one of the witnesses against him are either dead, have moved or are killed as the ex-con talks with him. And, most importantly, they all were known criminal-types. You'd think if the guy could show that all six turned out to have such questionable backgrounds that there'd be reason for the police to re-open the case, but he tells no one--remember, he IS kind of dumb. What else is dumb is that later he does a lot of things that would violate his parole in order to try to prove his innocence. Having a gun, involvement in a NEW robbery, not returning home at night, etc. all further prove the guy is a moron. Then, when he DOES learn who the guy behind the frame-up is, he doesn't go to the police--as he's fallen in love with that man's sister. Just how stupid can a guy be?!
"Convict's Code" is a pretty good B and might have earned a 4 despite its no-name cast--mostly because the story is pretty interesting-even if Dave is a certifiable idiot. However, the ending of the film is sort of like a "scene missing here" film--one where important action takes place off camera and it seems like this is dealt with in a slap-dash manner. It's a shame, but the ending is clearly an example of scene missing here film making--as the guy who REALLY committed the crime admits it but apparently says all this off camera!! Cheesy, clearly at the end and probably not a film to watch unless you are a B-movie fan, too.
By the way, the best thing about the film is a bit role played by Maude Eburne. She plays the most amazingly ambivalent landlady I've ever seen and she is pretty funny. Eburne played in a lot of films over the years and was always fun--including her stint as Dr. Christian's housekeeper in the RKO series.