MYTH: Keeping guns in the home increases personal protection.
TRUTH: Obviously, self defense is not a good argument against gun control since those who own firearms are actually more likely to be victims of homicide. Two studies published in The New England Journal of Medicine revealed that keeping a gun in the home increases the risk of both suicide and homicide. Keeping a gun in the home makes it 2.7 times more likely that someone will be a victim of homicide in your home (in almost all cases the victim is either related to or intimately acquainted with the murderer) (source) and 4.8 times more likely that someone will commit suicide (source). Guns make it more likely that a suicide attempt will be successful than if other means were used such as sleeping pills.

From http://www.guninformation.org/