Some time ago I came across this Harvard study on guns and self defense.
From the study:
4. Most purported self-defense gun uses are gun uses in escalating arguments, and are both socially undesirable and illegal
We analyzed data from two national random-digit-dial surveys conducted under the auspices of the Harvard Injury Control Research Center. Criminal court judges who read the self-reported accounts of the purported self-defense gun use rated a majority as being illegal, even assuming that the respondent had a permit to own and to carry a gun, and that the respondent had described the event honestly from his own perspective.
5. Firearms are used far more often to intimidate than in self-defense
Using data from a national random-digit-dial telephone survey conducted under the direction of the Harvard Injury Control Center, we examined the extent and nature of offensive gun use. We found that firearms are used far more often to frighten and intimidate than they are used in self-defense. All reported cases of criminal gun use, as well as many of the so-called self-defense gun uses, appear to be socially undesirable.
11. Self-defense gun use is rare and not more effective at preventing injury than other protective actions
Victims use guns in less than 1% of contact crimes, and women never use guns to protect themselves against sexual assault (in more than 300 cases). Victims using a gun were no less likely to be injured after taking protective action than victims using other forms of protective action. Compared to other protective actions, the National Crime Victimization Surveys provide little evidence that self-defense gun use is uniquely beneficial in reducing the likelihood of injury or property loss.
