Law enforcement sources say Adam Lanza was motivated by violent video games and a strong desire to kill more people than another infamous mass murderer. Sources say Lanza saw himself as being in direct competition with Anders Breivik, a Norwegian man who killed 77 people in July 2011. Breivik killed eight with a bombing in downtown Oslo. He then moved to a nearby island where hunted down and fatally shot 69 people, mostly teenagers attending a summer camp. Two officials who have been briefed on the Newtown, Conn., investigation say Lanza wanted to top Breivik's death toll and targeted nearby...