"She was very involved in the community and very well-respected," Briggs said.
Lanza's family was struggling to make sense of what happened and "trying to find whatever answers we can," his father, Peter Lanza, said in a statement late Saturday that also expressed sympathy for the victims' families.
Sandy Hook Elementary will be closed next week - some parents can't even conceive of sending their children back, Leidlein said - and officials are deciding what to do about the town's other schools.
Asked whether the town would recover, Maryann Jacob, a clerk in the school library who took cover in a storage room with 18 fourth-graders during the shooting rampage, said: "We have to. We have a lot of children left."
Contributing to this report were Associated Press writers Jim Fitzgerald, Bridget Murphy, Pat Eaton-Robb and Michael Melia in Newtown; Adam Geller in Southbury, Conn.; and Stephen Singer in Hartford, Conn.