According to my firearms instructor, who is personal friends with and a client of the attorney who authored the MS CCW law, the castle doctrine protects people from liability when they use deadly force against a person who it putting life and limb in jeopardy. However, if you miss the bad guy and kill the little girl riding her bicycle across the street, you can and will be charged with a crime, and will go to jail. Each of us in taking it upon ourselves to carry a deadly weapon are taking the responsibility for each and every bullet that exits our weapon. The castle doctrine only protects us when we kill/injure the bad guy, not when we miss and kill somebody else.