The gun apologists argue that lawful concealed carry gun holders pose no risk to the general public. However, 644 people (at least) would likely disagree if they were around to tell their side of the story.
The Violence Policy Center reports that since May 2007, 644 people have been killed by private citizens authorized to carry concealed handguns. These include 28 incidents of mass shootings and 14 deaths of law enforcement officers. About five out of six of the incidents were murder-suicides.
And none of the incidents involved self-defense.