Sandy Hook Elementary School shooting suspect Adam Lanza had no previous contact with police, according to Connecticut State Police spokesman Lt. Paul Vance.
The new information came during a news conference at the school on Monday morning.
Vance said two adults who were injured in the shooting survived. Previously Vance had said there was only one shooting survivor. ABC News reported one of the survivors was a teacher who was shot in the foot. There are no details yet on the second survivor.
Vance said authorities expect the survivors to give them important information. Vance also said investigators have "many, many witnesses to interview." Vance said when the Sandy Hook Elementary School children are interviewed, it will be done on the presence of investigators, professionals and their parents.
Twenty children and six adults were shot and killed at Sandy Hook Elementary School in Newtown, Connecticut on Friday. The suspected gunman, 20-year-old Adam Lanza, then shot and killed himself as police arrived.
"Major crime detectives are working 24 hours a day to answer question as to how and why," Vance said. "We have begun processing evidence."
Vance said he expects the school to be a crime scene for months.
There were no classes Monday in Sandy Hook, but officials hope to resume classes tomorrow for everyone except the Sandy Hook Elementary School students.