INDIANAPOLIS (WISH) — Two teens were behind bars on Thursday in Marion County after being arrested with handguns that had machine gun conversion devices on them.

According to the Indianapolis Metropolitan Police Department, three suspects wearing ski masks were seen Tuesday night near the entrance to the Von Maur department store at the Castleton Square Mall. The mall is on 82nd Street between I-465 and I-69 on the city’s northeast side.

Off-duty officers working security at the mall found the three suspects, who immediately ran. The officers caught two: 18-year-old Zachery Hunter Jr. and 19-year-old Octavious Reid. Online court records did not show any criminal charges filed against the teens on Thursday.

IMPD says it collected two handguns with machine gun conversion devices on them, high-capacity magazines, and ammunition.

On Thursday afternoon, it was unclear what the suspects might have been planning to do at the mall. IMPD was continuing to look for the third suspect in this case.

The case is just the latest where police have found people with machine gun conversion devices attached to handguns. The devices turn the guns into fully automatic weapons.

The Marion County Prosecutor’s Office has seen a staggering increase in the number of cases related to machine gun conversion devices in the last three years. In 2020, the officer recorded one case that led to charges for possession of a machine gun. In 2021, the office had 10 cases. In 2022, the count increased to 4. In 2023, that total is at 110 cases so far.

Officer Samone Burris, a spokeswoman for IMPD, told I-Team 8, “Unfortunately, that device has fallen into the wrong hands multiple times on too many occasions.”

The concern for IMPD is the capabilities of the guns with the devices on them. A fully automatic weapon can fire a lot of bullets in a short period of time. “That is concerning because, how do you combat that? How do you keep a community safe when they’re purchasing these devices for reckless intentions,” Burris said.