terrorized washington, d.c. they had no broader affiliation. virginia tech in 2007, the student who killed 32 people, most of them fellow students was lone wolf who then killed himself. last year, in tucson, arizona, congressman gabrielle giffords was shot and six people killed by a lone gunman who was found to be schizophrenic. >> it isn't that this fellow was born evil on to the planet. there is a life story here. the roots of this event reach back deep in to this person's early chapters of his life story. >> and more and more people with prior psychological problems are becoming desensitized. >> reality tv, facebook, instant messaging, iphones, all of it can contribute a sense that people aren't real. >> the calls for more gun control have begun. mayor michael bloomberg of new york wants to hear from president obama and governor romney. >> no matter where you stand on the second amendment, no matter where you stand on guns, we have a right to hear from both of them concretely,