The grainy, 10-second video shows Justin Gaines, 18, at Wild Bill's nightclub on November 1. The video is among the last confirmed sightings of Gaines.

WSB-TV Channel 2 has learned that a private investigator hired by the Gaines' family discovered the shot of Gaines after going through hours of the club's surveillance tapes.

Family members identified the person on the tape as Gaines.

VIDEO: Video Of Missing Gwinnett Teen Surfaces

The Gainesville College student disappeared after a night of partying at Wild Bill's with friends.

"You can see from the video clip that he shook hands with two of his friends that he met coming through the line," said private investigator Bob Poulnot. "He was just arriving at Wild Bill's. He was going through the cash window line."

Gaines disappeared after unsuccessfully trying to reach friends for a ride home from Wild Bill's. Poulnot said Gaines left the club and went to the parking lot.

A security guard at the club said he remembered seeing Gaines near closing time. "Right at that time, two females exited the building and were in an altercation, so the security guard had to deal with that and having done that he looked back down the parking lot aisle and didn't see Justin again," said Poulnot.

Several searches and a $50,000 reward have failed to turn up any sign of Gaines.

He is described as being 5"11' and 210 lbs. with a muscular build. He has blue eyes and brown hair with a short buzz cut. Both of his ears are pierced with diamond studs. He was last seen wearing a long sleeve, gray shirt with "Abercrombie" written on the front, blue jeans with holes and flip flops.

Anyone who has information on Gaines' whereabouts or anyone who has seen him is encouraged to call the anonymous tip line at 877-270-9500.