Connecticut School Shooting: Shooter's home offers clues to motive (VIDEO)

Police stand guard at the entrance to the Sandy School on December 15, 2012 in Newtown, Connecticut. The residents of an idyllic Connecticut town were reeling in horror from the massacre of 20 small children and six adults in one of the worst school shootings in US history. The heavily armed gunman shot dead 18 children inside Sandy Hook Elementary School, said Connecticut State Police spokesman Lieutenant Paul Vance. Two more died of their wounds in hospital. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)

(CBS) Newtown, Conn. - "CBS This Morning" senior correspondent John Miller reports on the latest developments in the investigation of the attack at Sandy Hook Elementary School, in Newtown, Connecticut on Friday.

Pictures: Conn. elementary school shooting

Miller says there have been reports that Adam Lanza, the shooting suspect, showed up at the school door and was buzzed in. He also notes there have been reports that he shot out a window and either walked through the glass or opened the door there.

According to Miller, investigators entered Adama Lanza's home that he shared with his mother, who was found fatally shot in the face at the residence, and found the 20-year-old's room "immaculate, everything was folded and put away, nothing strewn around."

Miller says it seems "telling in some ways, of the organized personality of someone who would go to such intricate and detailed planning for such a terrible crime."