They Made Me a Criminal opens in New York, depicting the latest victory in the ring for Johnny Bradfield (John Garfield), a young boxer who seems headed for a championship. When a reporter finds Bradfield drunk and carousing with women, and learns that the squeaky-clean image that he has cultivated is a complete lie, he threatens to blow the lid off the boxer's real life, and is beaten to death by Bradfield's manager. Bradfield, who was in a drunken stupor during the fight, is framed for the killing by his manager, who rolls him for his wallet, watch, and anything else of value, makes a run for it, and is killed in a fiery car accident. As far as the police are concerned, the case is closed, "Bradfield" having been identified in the wreck by the watch he was wearing. But Johnny Bradfield now has to disappear from New York and anyplace else he's ever been seen, in order to stay "dead." He is sent on his way by his crooked attorney with just a few dollars in his pocket, thumbing rides and walking west. Bradfield collapses one day from exhaustion and near starvation outside of a ranch in Arizona. The ranch is run by May Robson as part of a relief effort to help a group of boys from the New York slums -- Tommy (Billy Halop), Spit (Leo Gorcey), Dippy (Huntz Hall), T.B. (Gabriel Dell), Angel (Bobby Jordan), and Milty (Bernard Punsly) -- keep out of trouble. Identifying himself as "Jack Dorney", he first tries to see what he can get in the way of a free ride from the kids and Tommy's sister, Peggy (Gloria Dickson), who doesn't trust Dorney or his influence over the kids. Meanwhile, back in New York, one police detective, Phelan (Claude Rains), is convinced that the body found in the burned wreck of Johnny Bradfield's car wasn't Bradfield. Phelan is an outcast in his department for having once presented "conclusive" evidence in court against a man who was executed for murder, only to discover later that the man was innocent. He sees this as his chance to redeem himself and his career, and he is such a pariah that his chief gives him permission to follow up leads anywhere he needs to. At the ranch, Dorney takes a genuine liking to the kids, and sees Peggy as a kind of woman he's never known, who has no "angles" in her approach to life. The ranch may have to be sold, however, as there is no more money coming from the church in New York to keep it going. In order to save the ranch and set Peggy and the kids up in a roadside business pumping gas -- an idea of Tommy's -- Dorney decides to enter a prize fight for money against a barnstorming boxer. On the eve of the fight, however, Phelan shows up, drawn by a newspaper photo of Dorney, his face obscured but using the same unusual left-handed boxing stance he used as Johnny Bradfield. Dorney goes into the ring, and finds himself up against a brute who has already flattened two opponents in less than one round each, trying to hide his identity by fighting right-handed. He gets savaged, round after round, until Phelan tells him from ringside that he knows who he is. Free to use his left, Dorney saves himself. Phelan confronts him in the dressing room, and Johnny tells him he'll give him no trouble -- they're about to head back east, with Peggy and the kids trying to thank him, and it dawns on Phelan that possibly this is one case that might better be left "solved" officially the way it is already, even though it means the detective going back to his job as a laughing stock.