Oregon father is the latest armed civilian to confront a gunman in a U.S. mass shooting

The heroic "good guy with a gun" who can stop an attack even before law enforcement can arrive has long been a rallying cry by gun rights advocates, arguing that armed citizens can act as a first line of self-defense and public protection.

The heroic "good guy with a gun" who can stop an attack even before law enforcement can arrive has long been a rallying cry by gun rights advocates, arguing that armed citizens can act as a first line of self-defense and public protection.