Transcript for Dec. 14, 2012: Sandy Hook Elementary School shooting
Right here in Newtown Connecticut the site today of that shooting and this time gunfire aimed at elementary school children. We're here in front of the new time United Methodist Church where we've watched people gathering all these things along as tonight the details are still pouring in. There are 27 victims twenty children seven adults. And we've heard all day about the U credible response by teachers inside the school which is considered one of the leading schools and the nation. And also tonight we have a new image of the suspected shooter. As we tell you everything we know about who did it what kind of weapons and why. And would begin all of this with 20/20 anchor Chris coal mine he's here right now with me. Prince Diana's and almost an unimaginable see what we know so far is that inside this elementary school was a group of young kids. They were protected by their teachers and there was one deranged man who decided to take it all away. This morning the sandy hook elementary school was full of kids concerned about Christmas. And then at 9:40 AM shots rang out. I. Oracle. You're you're. Out. Inside little kids are under attack me hand. If rat king. Act last ram horrible things are happening. Teachers make sure they're safe and then do the unimaginable what is a teacher. She band's sound suddenly topped that thing and the pain that on gains from land. Did you hear in more bad noises. Turn. Long. The teachers com matched by a storm a police activity word of two shooters spark searches of the surrounding area. Children are rushed out of the school's single file hand in hand. Eyes squeezed shut. We got in there dying and current bank's. Strategy following jewelry outlets are as close. Her only. And I hands and added people science and I TJ and Helen different persons came and she Alanna if. Chaos complete chaos nobody knew or anyone wants is a mob scene of children and police didn't. Adults and Ellis mom AB and dozens of other family search for their kids as information starts to trickle in. And I heard that children are taken out bloody. I'm very scared worried about my thought hard about the other kids but I don't hear. It is terrifying incident and still terrified of them still in shock about it all I still don't know everything that happens. A situation that couldn't be any more terrifying kids at the mercy of a deranged gunman. And yet it keeps getting worse. Yeah. Here. Among the dead twenty year old gunman Adam Lanza and his mother who has a teacher's aide at the elementary school. He came with a bulletproof vest and four guns including two semiautomatic handguns and possibly an assault rifle say authorities. He killed so many of the kids she loves. It's a very very difficult seat. But the family members for all the responding first responders its extraction it's a tragic scene. And yet many more survived like little Ella who we'll still have a chance at a Merry Christmas it's over compared. You know then and. It's all these survivors they're so young. And that makes it so tragic and yet at the same time the families are hoping they're young enough Diane that they'll be able to forget. And move on their lives. Now the latest details whatever we've learned about why. Some suspect that your. It is always so important to us because that's the one thing we can learn the situation is what drove this person to this horrible thing and it now it's getting more confused. Authorities now believe. That the gunman's mother was found killed in her home not at the school. The question remains now larger than ever did this man go that is why did he attacked these kids with such intensity. So. That we know details are still has been saying we'll bring it up to date throughout this hour tonight as we especially right past.
This transcript has been automatically generated and may not be 100% accurate.