Both of Zimring’s pioneering studies, and several others since then, suggest that “guns do kill people” and support the position taken by gun control advocates that reducing availability of guns to violence-prone people would save lives, even if they substituted knives and clubs. Relative to criminal assaults involving small-caliber guns, the likelihood of death was more than doubled for criminal assaults involving medium-caliber guns and nearly five times greater for criminal assaults involving large-caliber guns. Based on these estimates, we ran a simulation that found that if the medium and large caliber guns had been replaced with small caliber guns in these criminal assaults, and all else had remained the same, it would have reduced gun homicides by nearly 40 percent.