You could break the law -- you could kill someone after a cold meditation about it or in the hottest of blood -- and sometimes it doesn't matter that much. That is, if you kill someone that's lower on the social and economic ladder, and especially if you repent of it.
But break the mores and you're an outcast.
I learned that back in high school, after I read The Stranger by Albert Camus. In the book, Mersault, the protagonist, was on trial for shooting an Arab. What shocked the court,though, was the fact that he started an affair soon after the death of his mother, who was in a nursing home.