Two Marine veterans played a key role in stopping a man who allegedly stabbed multiple victims in a Michigan Walmart. Matthew Kolakwoski had just left a checkout lane when he heard a worker scream that a man had a knife. He then heard a “mass of blood-curling screams from the back of the store,” mlive.com reported.

Nearly a dozen people were injured in the attack before citizens -- including Derrick Perry, who was armed with a gun -- confronted the suspect, authorities said.