(CNN) - The shooting spree at Sandy Hook Elementary School may have been motivated by a desire by Adam Lanza to outdo Anders Behring Breivik, the Norwegian man who killed 77 people in July 2011, law enforcement sources told CBS Evening News.
The unnamed sources said Lanza saw himself as being in direct competition with Breivik, who killed eight with a bombing in downtown Oslo before he moved to a nearby island where he hunted down and fatally shot 69 people.
According to the sources, the 20-year-old Lanza wanted to top Breivik's death toll and went to the Connecticut school on December 14 because it was the "easiest target" and had the "largest cluster of people."
This morning on "Early Start," CNN's Susan Candiotti breaks down the report.
READ MORE: Report: Sandy Hook shooter tried to emulate Norway massacre