Vince Weiguang Li,Do you know him?

Question

what build up him to do such thing? how you could pre-tell that you are not sitting close to the person like him?

Answer 1

????

Answer 2

I am sure this guy is seriously ill on his head thats why you can't really "pre-tell" who your sitting with that might be dangerous like him.But usually when you see people that are really quiet,like I mean when they barely make a utter,those people supress all their feelings inside and those are the most prone to become crazy.After this murder,I guess we learned a lesson not to sleep when your sitting beside a stranger.