The book in question is Always Bet on Red: A Rogue Gambler Western. The main character is John Denton, professional gambler, who rarely is in one place for long. He's older, mid 30s, lives on the road and by the cards. But he’s feeling the pull of home, and the closest thing he’s got to a home is in a little town in Texas where his best friend, Eli Jones, is sheriff. During a poker game, an agitated man bets the deed to a saloon he owns. Denton knows he has a winning hand, but Jones sees the saloon as a way to get out of the gun fighting business. Denton folds and Jones wins. Within an hour, Jones is dead. Denton saw the murderer, but the killer gets away. The next thing Denton knows, he’s being accused of the crime. The only way he can clear his name is to find the killer himself and bring him to justice even if it means defying the gambler code of honor.