I did some (very quick) comparisons to Britain's police force, which for the most part is not armed. I ignored the confounding effects of the illegality of guns

I did some (very quick) comparisons to Britain's police force, which for the most part is not armed. I ignored the confounding effects of the illegality of guns, assuming that most hardened criminals will be able to get one anyway (a convenient assumption, since I wasn't sure how to account for it any other way). British police are significantly less likely to be killed, or to kill, than U.S. officers. However, they are also much more likely to be assaulted, and injured in those assaults, than U.S. officers.