His handgun was strapped to his waist — he was wearing it so others could see it.
Technically, police said Mapes was arrested because he was carrying his weapon in a way that caused alarm and fear for others. He received a summons and was later released.
Once theater managers learned of the gun, they quickly evacuated several theaters in the building. About 30 people were affected. Witnesses said it was a frightening ordeal with the Aurora shooting still fresh in their minds.