The Sandy Hook and Arapahoe shooters displayed almost identical behavior. Both shootings occurred the week before Christmas break. Both intended to kill large numbers of people. They both shot themselves in the head as soon as the police showed up, and both were immediately assigned unbelievable motives by the press.
Lanza was supposedly jealous of his mother teaching at the school. Pierson was supposedly angry about being kicked off the debate team. Why would he want to kill other students because he was angry at a particular teacher?
There has been zero discussion from law enforcement about either one’s Internet communications prior to the shootings. Perhaps NSA forgot to track these two individuals.