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

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 shooter's violent path through Santa Monica, California leads to a deadly confrontation on a college campus. An examination of the shooter's mental health.

The city of Charleston, South Carolina is ripped apart by a shooting at a historic church. In the aftermath, the community is divided by the idea of forgiveness.

Survivors and first responders recount the 2012 movie theater shooting in Aurora, Colorado. A grieving family challenges the media.

Pulse Nightclub in Orlando, Florida is attacked by a shooter who kills 49 people, leaving an entire community devastated and traumatized by the loss.

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, Colorado and the myths that may have inspired the active shooter phenomenon. Documentary series finale.