I think it is horrible what does this guy did and he obviously had issues. If you don't know what happened, a 15 year old boy shot 5 people, one of them died. He killed himself afterwards. It is believed he did this because a girl he liked a lot rejected him on a date.
Most Helpful Girl
If it wasn't the rejection, something else would have set him off one day. It just happened to be rejection. He had issues, deeply rooted, serious issues.
I do think, however, that society's concept that guys are entitled to women plays a role in these shootings.
It is a phenomenon called running amok as another user pointed out (forgot who) read about it here: