Police believe a Minnesota high schooler would have carried out a long-planned massacre "within the next few weeks" if a suspicious neighbor hadn't called 911 on him. Seventeen-year-old John David LaDue was arrested Thursday and charged with four counts of attempted murder and more after police responded to a call from a neighbor who spotted him entering a storage unit. LaDue allegedly planned to kill his mother, father, and sister, then head to his high school where he would set off pressure-cooker bombs full of nails and ball bearings in the cafeteria. Afterwards, he planned to kill “as many students as he could.” LaDue's allegedly set off “practice bombs” around the community. According to the criminal complaint, LaDue told police that he'd originally planned his masacre for April 20, the anniversary of the 1999 Columbine shooting, but that date fell on Easter Sunday this year, when no one was at school.