Sources: Newtown Shooter Motivated by Norway Massacre
The motive for the murders at Sandy Hook Elementary School in Newtown, Connecticut may have been to try to kill more people than a Norweigian man murdered a year and a half ago.
In July 2011, Anders Breivik killed 77 people - 8 in a bombing near the government center in Oslo, 69 others - mostly teenagers - at a camp on a nearby island.
Two officials who were briefed by Connecticut investigators told CBS News that Lanza was obsessed with Breivik and was trying to top the Oslo shooter's body count.
Investigators say Lanza attacked the Sandy Hook school because it was an easy target with a large number of potential victims.
Officials have not revealed details about what led them to connect 20-year old Lanza to Breivik but have not managed to retrieve information from Lanza's laptop, which he attempted to destroy.
Investigators found a trove of violent video games in the basement of his home where Lanza practiced his shooting skills. They are now contacting people in the online gaming community, searching for anyone who may have been communicating with Lanza.
Lanza killed himself as Connecticut authorities closed in on the Sandy Hook school - unlike Breivik who surrendered and has been tried and sentenced for the deaths in Norway.
Lanza and his mother made multiple visits to nearby gun ranges where they practiced together.
On December 14th, Lanza used one weapon to kill his mother, then headed to the school with 3 other weapons where he took the lives of 20 children and 6 adults.
All three guns Lanza used in the attack on the Sandy Hook school were registered to his mother.