In Northglenn on Monday, Walmart shoppers were spectators to three arrests carried out by the FBI.

Shoppers were surprised to find the FBI. had trailed three suspects into the Walmart in Northglenn and used flash-bang grenades to subdue them.

Many shoppers ran from the noise screaming "Active Shooter!" and were placed into a back room and were locked inside for around 15 minutes until the all-clear was given.

The use of the flash-bang grenade was what the people had heard and thought was gunfire. No one was injured and the three were arrested.

Northglenn police arrived soon after and confirmed the action and the arrest, then assisted in removing a Jeep that was on the property that had the rear window broken out. No word on if the Jeep was involved or owned by any of the three that were put behind bars yesterday.

Almost like being in an episode of some crime show, isn't it?