"I read in the paper last week that a gun in the home is four times more likely to be used on a friend or family member that to be used defending the home against invasion."

That specific statement originated in a specific known article by ONE known radical anti-everything NUT. It has been thoroughly disproven by multiple other sources using official data from national, state, and in many cases local levels.

Are these the radical nuts you refer to?

New England Journal of Medicine:
Gun Ownership as a Risk Factor for Homicide in the Home

American Journal of Lifestyle Medicine:
Risks and Benefits of a Gun in the Home

American Journal of Epidemiology:
Guns in the Home and Risk of a Violent Death in the Home: Findings from a National Study