one of the heroes of the shooting incident in tucson saturday morning. he helped restrain jared loughner before first responders arrived on the scene. >> joe is here tonight and we will hear his remarkable story. there is a twist to a story we want to explore. when joe arrived on the scene. he was armed, had his gun ready with the safety off. in that moment of chaos, joe made a split second decision not to fire his gun. but what might have happened if he had? please welcome, joe zamudio. joe, thank you for being here. thank you for everything you did on saturday. >> thank you. >> all right, joe, before, just tell us what happened, saturday morning, tell us what you saw. >> well, kathleen, i went into the wal-greens to buy something. before i could even finish my transaction i heard the gunshots ring out. and i just reacted. i didn't think about it at all. i have heard that question more times than i can count.