Active Shooter: America Under Fire

Survivors and first responders recount the 2012 movie theater shooting in Aurora, Colo.; a grieving family challenges the media.

The 2015 shooting in San Bernardino, Calif. brings out a massive response from law enforcement, while a shocked community responds to homegrown terrorism.

In the aftermath of a shooting, Charleston, SC struggles with forgiveness.

Stories of loss and heroism during the 2013 shooting at the Washington Navy Yard; the shooter's sister recounts her brother's descent into violence.

A community is left devastated and traumatized by the shooting at Pulse Nightclub.

A shooter's violent path through Santa Monica, Calif., leads to a deadly confrontation on a college campus; an examination of the shooter's mental health.

A white supremacist's deadly attack on a Sikh temple in Oak Creek, Wisconsin and the heroic response by local police, transforms a community.

An exploration of the 1999 attack at a high school in Littleton, Colo., and the myths that may have inspired the active shooter phenomenon.