Surveillance footage from a liquor store near the Chick-fil-A in Boston’s Copley Square captured the “traumatizing” moment when dozens of people sprinted away after an off-duty police officer shot and killed a man wielding a knife inside the restaurant on Saturday evening.

The knife-wielding attacker shot and killed by an off-duty Boston police officer after refusing to back down from terrorizing Chick-fil-A patrons in the Back Bay this weekend has been identified.

Security footage obtained by the Globe shows a panicked crowd fleeing the Chick-fil-A restaurant in Copley Square Saturday evening at about the time an off-duty police officer shot and killed a person police say was wielding a knife and trying to stab people.