Forty-four years after the Tower shootings, another shooting occurs on the University of Texas campus. Survivors continue their lives while gun violence grows as a hot-button political issue. The physical wounds begin to heal, but the emotional ones remain.

The shooting becomes national news. Students return to classes a few days later. Law enforcement continues its investigation. An autopsy is performed on the sniper. A police officer is laid to rest. Victims start their road to recovery.

Ninety-six minutes after the shooting began, the sniper is dead. Everyone nearby converges on campus. Law enforcement and journalists work to identify the dead. Hospitals struggle with the influx of patients. Friends and families mourn their loved ones.

More law enforcement officers swarm campus and join the efforts to stop the shooter. In the tower, a chaotic situation unfolds as a handful of officers and civilians make their way to the observation deck and exchange fire with the sniper.

A police officer assigned to divert traffic from the campus area decides to head into the action. The bookstore employee heads toward the tower and teams up with law enforcement. Together, they hatch a plan to stop the sniper.

The shooting continues along The Drag, a nearby street full of shops and restaurants. An employee of the university bookstore helps a wounded boy. More people join the rescue efforts. Students eating lunch and shopping take cover or run to safety. Police officers, students, and others get their guns and begin firing back at the sniper.

The sniper opens fire on the University of Texas campus and the surrounding area. He shoots a pregnant woman, leaving her on hot concrete in the middle of the gunfire. A local radio reporter heads to the scene. Students in a Shakespeare class watch out the window as a police officer is shot.

It's August 1, 1966, a hot summer day in Austin, Texas. Not that many people are on the University of Texas campus, except the students enrolled in summer classes. As Monday morning classes start, a 25-year-old former Marine has just killed his wife and mother. He packs the trunk of his car with seven guns and enough supplies to last him days. Then he drives to campus.

On August 1, 1966, a sniper climbed the steps of the University of Texas at Austin's 27-story tower. Seventeen people were killed and more than 30 others were injured. Fifty-six years later, mass shootings make headlines nearly every week. And the University of Texas tower looms over campus, a reminder of one of the first mass school shootings in United States history that has long been forgotten.

In season four of "Darkness," host Sara Kinney walks through the day of the University of Texas Tower shooting and outlines its legacy among the decades-long epidemic of gun violence in schools. Hear from survivors, heroes and family members about their day in 1966, their lives since then and the state of gun control today.

As the bloody year of 1885 draws to a close and 1886 begins, the police are no closer to solving the vicious crimes that rattled Austin. Even more than a century later, no one knows for sure who killed these women or why. This episode explores the various theories, from the effects of the moon to the possibility that Jack the Ripper started in Texas.