What's up with this school??

This past Wednesday a female Chinese graduate student at Virginia Tech University was murdered by another fellow Chinese student. The victim was decapitated with a kitchen knife in one of the schools cafeterias. Witnesses say the two students did not seem to be arguing and in fact were having a quiet conversation prior to the attack. Obviously this is a sad event for Virginia Tech which was also the scene of a shooting spree not long ago which left over 30 students and teachers dead. The suspect had no priors and up to this point no motive for the murder. The man was found by police holding the victims severed head in his hands. The big question here is what drove this guy to do such a heinous act!