I Forgot the Name of That ___! discussion

I need help...I read a book about 10 years ago..it was about a woman who left her abusive husband...she cut off her hair and dyed it...she turned up on this mans doorstep and he took her in..the husband came looking for her and found her...the man she was staying with well they fell in love. the husband found her and the guy killed him. I think he was like ex military or something. I think the story took place in like Arizona or something like that...