The Gunslinger and the Lady by Anne Stuart

The Gunslinger…
Mad Billy Maddox, aka the Angel of Death, comes to the tiny town in Johnson County, Wyoming as a gun for hire to scare away the settlers. He’s a man who makes his living with his guns, and he never expects to find someone to make him want to change his ways.
The Lady…
Sara is the sweet and shy wife of the biggest bully in town. She’s learned not to let anything scare her, but the way Will Maddox looks at her shakes her up far worse than her husband’s heavy fists. She knows she should hate him, but she can’t.
Together…
He’s a bad man, and she’s a good woman. There’s no future for them in the wild Wyoming territory. But Maddox is a man who gets what he wants, no matter how high the price, and he wants Sara. Not even the fact that he killed her husband will get in his way.
(Previously published as “Dangerous Touch” in the One Night With a Rogue anthology)