Four teens playing basketball inside a Portland area middle school were caught after Sonitrol Pacific’s audio security system detected them March 12.

Operator Robin Goings received an impact-activated alarm from the school late Saturday afternoon. He heard security audio of what sounded like people playing ball and dispatched the school district’s guard service to investigate.

When the guard arrived at the school, he found four teenage boys playing basketball in the gym in the dark. He detained the trespassers and called police.

The four were released to their parents’ custody after the police and school district completed their investigation.