KingBreaker (2010)

Hank lives two completely different lives concealing one from another. By day he's Hank, a family man with a marriage on the rocks with his wife Miriam that thinks he's having an affair, but by night Hank turns into "Tom Dunn", a sadistic, quirky, cold-blooded hit man for hire with a strict code of conduct. As Tom continues to take increasingly risky but lucrative jobs from his handler Jackie that are passed down down to him from his mysterious boss Walter all while his marriage is falling apart, Tom is pushed to his limits when he discoverers he's actually working for the Mexican Drug Cartel sending his two lives on a collision course into one another.