Denver police have pointed to a YouTube video they say shows a possible suspect in the weekend shooting at a marijuana celebration that injured two people and scattered a crowd of thousands.

The shooting on Saturday took place during the outdoor celebration of the first 4/20 counterculture holiday since Colorado legalized marijuana. Witnesses said as many as 10 shots could be heard at about 5 p.m. Denver police spent much of Sunday scanning video taken at the event.

Police spokesman Sonny Jackson said that the suspect is shown in the video walking in a crowd moving away from the scene of the shooting as sirens wail in the background.

He says the suspect is a black male who was wearing a brown and white checkered shirt.