I was actually driving past the school when I saw the squads approaching.  Swat was also called in although I didn’t see them.  This is part of the regular policy when un-authorized people gain access to the school.

Hello, this is Roderick Wade, assistant principal at Kennedy High School. We initiated a lockdown at 11:45 a.m. today when four unidentified male subjects were seen in the school after they had originally been denied access at the main entrance by the school’s security staff. We believe the four subjects left the building when the lockdown was initiated. Bloomington Police Department responded immediately, and is currently investigating the incident. The lockdown was a precautionary step in an effort to identify the four subjects who were not students. The school came off lockdown approximately 45 minutes later. We ask that you continue to encourage your child to report suspicious activity. Thank you very much for your cooperation.