The Fighting Coward (1935)

Police detective Bob Horton (Ray Walker) is about to be engaged to marry Marie Russell (Joan Woodbury), the daughter of Police Chief John Russell (Earl Dwire), who thinks of Bob as his own son. Tom Anderson, the district attorney, is murdered and Bob manages to discover where the killer is hiding. Chief Russell sends a detail to help Bob who, before they arrive is astonished to learn that the killer is his own father, Jim Horton (William Farnum). Bob allows him to escape, and then returns to headquarters and resigns. Bob learns that his father is somehow involved with a gang of counterfeiters led by Krane (Mathew Betz).