and visit with families of the victims. we're joined by randi kaye, drew griffen and dr. sanja gupta. take us through what happened. you said this started with a tweet from representative giffords. >> it did. the congresswoman does try to squeeze in about eight or nine events. saturday morning she sent out a tweet at 9:58 a.m. local time here inviting people to her first event called "congress on the corner." she wanted people to come and ask her questions. that was at 9:58. 12 minutes later, she was shot in the head, gunned down. it's unclear at this point because we don't know a motive about the suspect, it's unclear if maybe he had seen that tweet and that's what prompted him to go to that safeway supermarket or if he was already there waiting for her. >> i want to put up the mugshot that we got today of this alleged shooter. this is the first indication of what he looks like now. we've seen a lot of pictures with him with hair. his head is shaved. he's got -- you can interpret the look he has. drew, what do we know about this guy? >> well, we know apparently that his mental deterioration began