The short story you're describing is likely "Trap of Gold" or "The Man Who Stole a City," both of which are part of Louis L’Amour’s vast collection of Western tales. However, based on the specific details about the accidental shooting and the subsequent personal drama, it might also be found in collections like "The Strong Shall Live" or "The Collected Short Stories of Louis L’Amour."

Louis L’Amour wrote many stories about lawmen, personal redemption, and complex relationships, often blending themes of tragedy and reconciliation. If you don't see a title that matches, searching through The Collected Short Stories volumes might uncover the exact story, as they compile most of his shorter works.