Sandy Hook gunman kept 'score sheet' of past mass killings

March 18, 2013 4:46:00 PM PDT
There are chilling new details about the gunman who went on the shooting rampage at Sandy Hook Elementary School last December.

The New York Daily News is reporting Adam Lanza kept a "score sheet" of past mass killings and created a database of killing sprees and attempted murders on his home computer.

The newspaper reports that Lanza had been studying mass killings for years before he carried out the Connecticut attack. The shooting left 20 students and six adults dead. Lanza killed himself after the massacre.