ROSS: Our reporting doesn't confirm that. And the fact is, in Connecticut, there is a waiting period to buy any weapon. You need a permit to buy a handgun, not a long rifle. But even so, there's a waiting period. And if there was an attempt to buy one in a short period of time, that wouldn't work.
STEPHANOPOULOS: There had also been some information earlier that the shooter's mom may have had some connection to Sandy Hook, may have been a substitute teacher or a volunteer there, but the superintendent has now said that is not the case. So do we have any better idea of why Adam Lanza chose this school?
ROSS: Well, the superintendent has said that the mother, Nancy Lanza, did not work there, she was not a teacher, but her relatives say she did volunteer as a teacher's aide at Sandy Hook apparently around the same time that Adam was a student there. He was a troubled young man, according to friends, and according to relatives, Nancy had many issues with the school district about how they were treating him and handling his particular special needs, so that may have been a source of conflict.
And at one point, according to the aunt of Adam, the mother pulled Adam out of the public school system and home-schooled him because of her unhappiness with the way he was being treated at school.
STEPHANOPOULOS: And the police also spent an awful lot of time at that -- at the home, which is also a crime scene, of course, where the mother was murdered. What else have they been able to find inside that home?
ROSS: Well, they say they have made good progress from evidence found in the home, unspecified, as to the why and the motive. We don't know if that means there was a note or some sort of a video left, but they say they are making progress in determining a motive here that was involved in which, you know, he started the day by shooting his mother and then drove about 10 minutes to the school. So he had a very determined mission in his head when he started that day, Friday.
STEPHANOPOULOS: I saw one report that the hard drive -- the hard drive of his computer at the home had been broken. Is that true?
ROSS: We haven't been able to confirm that. There have been a number of reports. It's hard to know. Police are, they say, purposely keeping a lot of these things close to the vest as they put together a full picture.
The best information, really, about Adam and his background comes from former classmates who attended school with him and say he was awkward and socially very ill at ease around people, didn't like to be talked to. He was a member of the tech club at his high school. Friends say he was very bright, very smart, but very withdrawn.
STEPHANOPOULOS: But the mystery still, why he did this.
ROSS: That remains a serious question. There seems to be some connection, at least in his twisted way of thinking, that put him on that path, but it's not certain yet just what that was, George.
STEPHANOPOULOS: OK. Brian Ross, thanks very much.
And as we said earlier, so many Americans joining in to honor and remember those lost on Friday and this whole community. On "Saturday Night Live" last night, a children's choir sang "Silent Night."
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STEPHANOPOULOS: And here in Newtown, a continuous vigil, as the community comes together in tears and prayer. ABC's Juju Chang is at St. Rose of Lima Church this morning. Good morning, Juju.