The thing about the four rules of gun safety is that you have to break at least two of them to do any material damage (from Wikipedia):

  1. All guns are always loaded. Even if they are not, treat them as if they are.
  2. Never let the muzzle cover anything you are not willing to destroy. (For those who insist that this particular gun is unloaded, see Rule 1.)
  3. Keep your finger off the trigger till your sights are on the target.
  4. Identify your target, and what is behind it. Never shoot at anything that you have not positively identified.

And now to the news:

Lee County sheriff’s deputies say a Sanford man shot and killed himself while showing friends the safety of his new gun.

The captain says Butler showed them the safety and how the gun would not fire. Johnson says after Butler pulled the trigger and it didn’t fire, he showed them the slide action, put the gun to his head and pulled the trigger again.

Johnson says Butler apparently failed to re-engage the safety.

There are various apocrypha to go with the above rules, including “the safety is what’s in between your ears”, but even putting aside the issue of mechanical gun safeties, for this to happen, two of the four rules had to be disobeyed. If only rule #1 had been broken, the gun would have discharged non-lethally in to a couch or wall. If only rule #2 had been broken, the guy would have never pulled the trigger while pointing it at his head, because he assumed that it, like every gun you ever handle, was loaded.