Some people tend to go off the tangent when they hear bad news or are in a state of shock. Similar thing happened with a man who has been identified by the New York Police as Jiverly Voong (Wong).
Jiverly Voong was an ex employee of IBM and has been laid off recently. Perhaps the shock of losing his job made him go over the edge and on a shooting spree inside the building.
As to why he picked that particular place or whether if at all his job discontinuation was in fact the reason for his going on a rampage, only time and further investigation will tell.
Jiverly Voong Wiki
Jiverly Voong is a 41 year old Binghampton resident and is responsible for killing at least 13 people when I last checked with the reporters on the ground. He is of Asian descent and I can tell you right off the bat he is not Indian or south Asian but more of the Philipino Korean variety. (Perhaps even a viet). Jiverly lost his mind and stormed the American Civic Association in Binghamton, N.Y on this day.
I will continue to update this page as and when new information arrives or when his photo (pic) becomes available in the public.