0 back in the washington, d.c. bureau of cnn. wolf? jake, thanks very much. happening now, we have extraordinary new details about the gunman who killed 12 people at the washington navy yard. police, family and friends, they are painting a picture of a deeply troubled individual who heard voices, felt vibrations, before he apparently snapped. we also are getting new information right now about the weapon. authorities say alexis walked into the navy yard with a shotgun. we are going to tell you where and how he managed to buy that weapon. and a city known for its tough gun laws is now in mourning. amid deep anger over apparent security lapses. i ll speak live in the coming minutes with the washington, d.c. mayor, vincent gray. i m wolf blitzer in washington. you re in the situation room. a day after gunfire and sirens echoed in the nation s capital, mourning has begun for the 12 people shot dead at the washington navy yard. today, we finally learned the identities of all of them.