http://hellobeautiful.com/2014/03/14/why-the-houston-dad-who-shot-and-killed-his-daughters-boyfriend-likely-wont-face-charges/

Cliffs:

Man hears noises coming from Daughters bedroom.
Enters with gun to find boy in daughters bed.
Daughter denies she knows him .
Man shoots boy.
Daughter later says it was her boyfriend.
Man faces no criminal charges.