I'm the kind of person that I would have kept trying to help him no matter how many times he cried wolf... Having had a past where I had contemplated suicide, I have some knowledge of what it is like. If something were to happen on here (or anywhere I found online) I would contact the mods who may have access to his email, ip, or anything else to possibly ID him in real life, then I would probably call my aunt's boyfriend who is a cop and ask if he knew anyway to track him down/help him.
As to suicide: It absolutely is a very selfish thing to do, especially doing it the way he did... And it sucks... If anyone wants to talk more about it or about my experiences with it, please PM me as I am always willing to talk, especially for those who don't understand or those who know the feeling and want to know the solution.