Chilling video appears to document Thousand Oaks mass shooting

Chilling video appears to document terrifying moments inside the Borderline Bar and Grill during the mass shooting.

The sounds of gunshots can be heard in the video.

Dallas Knapp posted the video to Instagram with the message, "I looked him in his eyes while he killed my friends I hope he rots in hell for eternity. The guy you see is the murderer and the shots are him shooting the wounded on the ground."

On Instagram Knapp also posted a photo with an apparent victim of the shooting saying, "A hero."

The identity of the victim in the photo has not been released. Multiple people wrote they were sorry for his loss.

Knapp also wrote in a post on Instagram, "That bastard will rot in f**king hell I have video of that scum of the earth I watched him kill and I would have gladly died to stop him. This man was scum nothing less killing women and men alike. I wish you are damned in hell."