Watch: Trailer for 'One Pulse,' Doc on Orlando Gay Club Shooting, Debuts

A trailer for an upcoming documentary about the Pulse gay club massacre in Orlando, Fla. last year - the worst mass shooting incident in modern U.S. history - has hit the web.

"One Pulse" will feature victims of the attack, carried out by Omar Mateen, highlighting their stories and exploring what law enforcement did wrong. Deadline reports the film will focus on what happened in the 192 minutes before police got to the scene, where Mateen was able to take over the club, killing 49 people and wounding 53 more.

Directed by documentarian Charlie Minn, who has helmed 23 docs, spoke with Deadline about "One Pulse" and the shooting.

"Police first exchanged gunfire with the shooter and then decided not to pursue him into the bathroom. That was the most critical decision of that night," Minn said. He added it's been almost a year since the attack but a FBI report has not been released. Minn said there are several questions about the shooting, like why police did not go into the bathroom to pursue and take down the shooter.

The trailer drops not long after newly released video footage from bodycams on officers responding to the Pulse shooting. The video shows shattered glass inside the club, the sounds of automatic gunfire and an officer shouting to the gunman, "Come out with your hands up or you will die!" Read more about that, and watch some of the footage, by clicking here.

Watch the "One Pulse" trailer below.