Matthew Kolakowski was shopping with his daughter at a Michigan Walmart when he heard screams and saw a man with a knife.

O'Brien and Kolakowski, who are brothers-in-law, were visiting the Walmart to pick up supplies for a family vacation when the stabbing broke out.

Derrick Perry says he's no hero for helping subdue Bradford James Gille, who faces terrorism and assault charges for allegedly stabbing 11 people.