i m alex witt. it is a day of questions and fresh insight about the sandy hook elementary school shooting. there is information about the gunman, how he entered the school and killed 20 children and six adults before he killed himself. we have established the point of entry. it s believed he was not voluntarily let into the school at all. that he forced his way into the school. but that s as far as we can go on that. in a moment, chris janzen in connecticut with more on that news conference. first compelling new information about the shooter and what he did in the days before the attack. nbc s pete williams is in washington. pete with a good day, what have you learned? reporter: alex, the connecticut authorities have not yet formally identified the gunman, but we re been told and i think it s widely known it s adam lanza is his name, 20 years old who was living with his mother. they say the shooting actually began that morning about three miles from the school at the ho