So today is the five-year anniversary of the Columbine school shooting. There’s a great article here on Slate on the minds of the killers:

The FBI and its team of psychiatrists and psychologists … believe they know why Harris and Klebold killed, and their explanation is both more reassuring and more troubling than our misguided conclusions. Three months after the massacre, the FBI convened a summit in Leesburg, Va., that included world-renowned mental health experts, including Michigan State University psychiatrist Dr. Frank Ochberg, as well as Supervisory Special Agent Dwayne Fuselier, the FBI’s lead Columbine investigator and a clinical psychologist. Fuselier and Ochberg share their conclusions publicly here for the first time.

I had completely forgot Harris, described in Slate as a clinical psychopath, had fantasized about hijacking a plane and crashing it into New York City.
From the April 27, 1999 Baltimore Sun:

LITTLETON, Colo. — The two teen-age gunmen who went on a murderous rampage at a suburban high school here wanted to kill 500 classmates and neighbors, then hijack a plane and crash it into New York City, authorities said yesterday.
….
Davis, the spokesman for the Jefferson County Sheriff’s Department, said Harris wrote in his diary that he and “Vodka,” his nickname for Klebold, planned to kill hundreds of students. The pair then would carry their rampage into the surrounding neighborhood before hijacking a plane that would be crashed into New York City, Davis said. Other Harris entries have the two young suspects escaping to an island.
It is unknown whether the suspects hoped to carry out those plans. Davis said the evidence has yet to show they planned to hijack a plane. Davis speculated New York was chosen as a target because of ” population density.