Horrifying footage shows a 17-year-old gunman opening fire during a Halloween celebration in downtown Orlando, leaving two people dead – and a heroic police officer tackling the gunman.

A video released by Orlando police on Friday allegedly shows Jaylen Dwayne Edgar walking through the crowd in a yellow shirt and backpack before starting shooting, sending costumed revelers running for their lives.

Edgar tries to flee the scene, but a police officer who saw him pull the trigger immediately tackles him to the ground alone before three other police officers pounce on him.

“Get on the ground!” The officer repeatedly yells at the teen amid the chaos, bodycam footage from the arresting officer shows.

The shooter says, “It’s not me,” but is quickly taken into custody.

“I saw him shoot,” police say in the clip.

At least two people were killed and six others were injured in the mass shooting, police said.