This class photo was taken weeks before the Columbine High School shooting. (April 20, 1999) Eric Harris and Dylan Klebold, who would go on to kill 12 of their classmates and a teacher, can be seen seated at the top left corner posing their hands like guns and pointing towards the camera. [640×465]

On April 20, 1999, the Columbine High School shooting left all of America in shock after teenagers Eric Harris and Dylan Klebold massacred 12 of their classmates and one teacher before turning their guns on themselves. In the aftermath, everyone attempted to make sense of how the shooting could have happened, how two “normal” teens could be capable of something like this. Parents, police, pundits, and survivors alike searched for clues and retroactive warnings in the pre-shooting behaviors of Harris and Klebold.

Perhaps the most chilling artifact uncovered in the wake of the shooting was this class photo taken a few weeks before the massacre, which appears rather standard at first. But a closer look at the top left corner shows the two shooters posing their hands like guns and pointing them at the camera.