Lock and alarm all entrances but one so they open from inside only. Install video at said entrances, inform staff and students of punishment for anyone opening said entrances. Have two armed guards at the main entrance with metal walk through detectors.
Lock and alarm all entrances but one so they open from inside only. Install video at said entrances, inform staff and students of punishment for anyone opening said entrances. Have two armed guards at the main entrance with metal walk through detectors.