Texas law

Here is a story from Arlington: Husband kills wife's lover; wife charged - CNN.com I have to say that I agree that the wife is responsible for her lover's death. But, there are a few things that jump out at me in the story:

1. No one seems to question that it was alright to shoot a supposed rapist in the head when he was trying to get away. They are not suggesting that he was protecting his wife, just that he is justified in shooting a rapist in these circumstances.
2. He did not evidently question why his wife was in the driveway in a robe.
3. He happened to be carrying a gun. This point particularly stuck out - this tragedy would not have happened if people could not just walk around with a gun. He is not a police office or a security with a reason to be carrying a gun - he is an employee of a real estate firm coming home from a card game.