Teacher says gunman was loner who didn't feel pain

"There was certainly no indication of anything unusual that lets you think that a kid's going to do something like that," said McDade, who works in finance in New York. "There was nothing that would indicate anything going on behind the scenes that would lead to this horrible mess."

He recalled Adam Lanza as "a very bright kid."

Olivia DeVivo, a student at the University of Connecticut, was in Adam Lanza's 10th grade English class.

"He was very different and very shy and didn't make an effort to interact with anybody," she said.

DeVivo said Lanza always carried a briefcase and wore his shirts buttoned up to the top button. She said he seemed bright but never really participated in class.

"Now looking back, it's kind of like 'OK, he had all these signs,' but you can't say every shy person would do something like this."

On Saturday, a police car was parked in the driveway of the Stamford, Conn., home of Lanza's father, Peter Lanza. An officer stopped reporters who tried to approach the house.

Associated Press writers Michael Melia and Jim Fitzgerald in Newtown, Conn., and Denise Lavoie in Stamford, Conn., contributed to this report.