Killer McCoy

Tommy is a tough, street-smart fighter who climbs from the streets to professional boxing. He rises from a pool hustler and newsboy background, gaining confidence and power as he moves up the ranks. His career is steered by the gamblers around him, especially the bookie Caighn, who seeks to control his victories. He ultimately faces a moral crossroads, choosing to defy the betting schemes and, at the end, to quit boxing for a chance at a normal life with Sheila.

Sheila is Caighn's daughter, introduced as a seemingly respectable young woman who becomes involved with Tommy. She falls for him and ignores warnings about her father's gambling world, creating a conflict between love and loyalty. Her relationship with Tommy complicates both their lives as the bookie’s daughter intersects with criminal schemes. Ultimately, Sheila helps protect Tommy, contributing to the couple’s path toward a safer life.

Johnny Martin is the aging boxing champion who is out of shape due to years away from the ring. Tommy knocks him out with a left hand, an act that leads to Martin's death and sets a dangerous tone for the gambling world. Martin’s fate serves as a cautionary backdrop for the brutal cost of the sport and the manipulation around it.

Cecil Walsh is a major gambler who discovers Tommy's ties to Caighn and uses his knowledge to drive the betting strategy. He is one of the key players in orchestrating the plot against Tommy, including the kidnapping to force a poor performance in a championship fight. Walsh embodies the calculating, cold-blooded nature of the sport’s gambling underworld.

Jim Caighn is the bookmaker who buys Tommy's contract and profits from his losses, presenting himself as a benevolent supporter while secretly manipulating outcomes. He hides his gambling business behind a legitimate front, maintaining control over Tommy and his family through debt and influence. His role drives the central conflict as Tommy is forced to confront the consequences of the betting system.

Brian McCoy is Tommy's father, a former song-and-dance man whose drinking and debts burden the family and tie him to Caighn's control. He struggles to protect his son while being pulled deeper into the gambling web. He actively participates in the escape from the kidnappers, demonstrating loyalty and courage in a dangerous situation.

Father Ryan is the priest who presides over a charity boxing event and serves as a moral anchor for the story. He represents the constructive, redemptive side of boxing and community support, offering guidance to Tommy and others as they confront crime and temptation. His presence underscores the film’s themes of faith and integrity amid corruption.