Three teens were arrested Saturday night and a handgun was found after a disturbance at the Cinemark movie theater at Louis Joliet Mall.
No one was hurt, but the incident involved a foot chase to the parking lot of the nearby Home2Suites hotel.
Cinemark staff were escorting the three teens out of the theater when they ran, police said.
Joliet police said one of their officers was working security at the mall and was notified about the disturbance, which occurred about 7:44 p.m. Police learned one of the people involved may have had a handgun as other officers were called to the scene.
Police caught up with the three teens in the Home2Suites parking lot, where they were arrested without incident.
The path where the teens had run was searched, and a .45-caliber handgun was found on the ground, police said.
The names of the teens were not released because they are juveniles.
A 17-year-old male was determined to have had the gun. He was arrested on charges of aggravated unlawful use of a weapon, mob action and disorderly conduct.
Two 16-year-olds, one male and one female, were arrested on charges of mob action and disorderly conduct.
The 17-year-old and the female were taken to River Valley Justice Center. The 16-year-old male was released to a parent.
Police said it was an isolated incident that posed no danger to the community.