Campbell, holding the camera, moves slowly to his right, filming the line; Campbell is heard twice asking, "Is this OK?"
"When I was approaching the line, an officer told me to stop and step back, so I stepped back 5 or 10 feet and started filming, and I asked if that was OK," he explained Monday.
He said there was no reply until an officer raised a weapon and fired, striking him in the upper right thigh with a nonlethal projectile; the video ends with his crying out in pain.
"At first I was just stunned, and in an immense amount of pain," he said. "It was just shock. I was extremely shaken. And since then what I'm really wondering is what was going through that person's head that made him think it was OK to shoot another person with a less-than-lethal weapon for doing absolutely nothing wrong."