Off-duty security guard saves a life with legally carried gun. On tonight's Hero of the Day, Cam Edwards shares a story from Boston, Massachusetts, where a patient at a general hospital bipolar clinic attacked his doctor with a knife. While others were fleeing from the screams and stabbings, the armed citizen burst into the room and ordered the assailant to drop the knife. When he did not comply, the off-duty security guard fired his legally owned gun at the man. The doctor is currently recovering from her wounds.