Many people keep a gun to protect themselves and their family at home.  If you're in this group, you should read about Kevin Monahan who shot and killed a woman who was a passenger in a car that mistakenly drove up his driveway.   

According to the article, Mr. Monahan and his wife were awakened by the sound of vehicles in his driveway.  He told his wife to hide inside and went outside with a pump action 20 gauge shotgun.  First, he fires a warning shot into the air.  Then, after losing his balance, shoots a shot into the car that killed Kaylin Gillis.  

There are many indicators to me that Mr. Monahan was not trained in self-defense because he did a lot of things wrong:

1. If he thought he was under siege he should not have gone outside.  He lost most of his defensive capability by going outside.  If three cars of people are trying to attack you, you should barricade yourself inside your house and create an advantage with cover and concealment.  Also, call 911!
2. He said he only wanted to protect his wife.  She was safe inside.  A self-defense shooting is only legally justified if there is an imminent threat of death or grievous bodily injury.  Nothing in the article suggested Mr. Monahan should have felt that level of threat.  Also remember, you should not shoot to protect property. 
3. He fired a warning shot.   No, no, no, no.  Seriously, don't do it.
4. If he really did accidentally shoot the shot that killed Ms. Gillis (its clear the judge didn't believe him), then Mr. Monahan was not applying the rules of safe gun handling.  The only way a gun fires is if you pull the trigger.  This can happen accidentally if you rest your finger on the trigger instead of following the second rule of the NRA's rules for safe gun handling:  ALWAYS keep your finger off of the trigger until ready to shoot.

I want to encourage everyone who keeps a gun for self-protection to spend time learning about scenarios you might be put in and thinking about how you would handle them.  Getting some hands-on live fire training is also important.