"Research has shown that a gun kept in the home is 43 times more likely to kill a member of the household, or friend, than an intruder.(Arthur Kellermann and Donald Reay. "Protection or Peril? An Analysis of Firearm Related Deaths in the Home." The New England Journal of Medicine, vol. 314, no. 24, June 1986, pp. 1557-60.) The use of a firearm to resist a violent assault actually increases the victim's risk of injury and death(FE Zimring, Firearms, violence, and public policy, Scientific American, vol. 265, 1991, p. 48)."
"Keeping a gun in the home carries a murder risk 2.7 times greater than not keeping one. That is, excluding many other factors such as previous history of violence, class, race, etc., a household with a gun is 2.7 times more likely to experience a murder than a household without one, even while there was no significant increase in the risk of non-gun homicides. " (Arthur Kellermann et. al., "Gun Ownership as a Risk Factor for Homicide in the Home," The New England Journal of Medicine, October 7, 1993, pp. 1084-1091)
"The present study, based on a sample of eighteen countries, confirms the result of previous work based on the 14 countries surveyed during the first International Crime Survey. Substantial correlations were found between gun ownership and gun-related as well as total homicide and suicide rates. Of the recorded homicide rates, 16% were commited unintentionally. Widespread gun ownership has not been found to reduce the likelihood of fatal events committed with other means. Thus, people do not turn to knives and other potententially lethal weapons less often when more guns are available, but more guns usually means more victims of homicide and suicide." (International Crime Victim Survey 2004)