The Pueblo Chieftain reported that the boy is one of three accused of breaking into the Fair's VIP building early Thursday. The trio took televisions, a laptop and an empty cash register.
The suspects managed to lock themselves in the building and had to break out.
A local television station aired surveillance video of the suspect dressed as Batman. After the video aired, the boy turned himself in to police. Authorities plan to seek charges including burglary and criminal mischief.
The boy wasn't named because of his age. Police were still seeking the other two suspects.