December 14th, 2012, Sandy Hook Elementary School
Perhaps the most notorious and heart-wrenching school shooting in U.S. history, Adam Lanza's rampage at Sandy Hook Elementary School in Newtown, Connecticut, left Americans wondering what could possibly inspire a young man to kill with such seeming indiscrimination.
It was less than two weeks before Christmas when Lanza got a hold of the weapons over which he and his mother had bonded, killing her with her own .22-caliber Savage MK II-F rifle as she laid in bed.
Lanza then took his mother's Bushmaster XM15-E2S rifle to Sandy Hook Elementary, where his mother had worked as a volunteer, and opened fire, killing twenty children and six adult staffers. It was the second most deadly mass shooting by a single gunman in America.