The Association of Firearm Caliber With Likelihood of Death From Gunshot Injury in Criminal Assaults

Abstract

Key Points Question Is there an association between the likelihood of death for firearms shooting victims and the caliber of the firearm? Findings A cross-sectional study using 5 years of data extracted from investigation files kept by the Boston Police Department determined that the case-fatality rates of assaults inflicting gunshot injury increased significantly with the caliber of the firearm. Caliber was not significantly correlated with other observable characteristics of the assault, including indicators of intent and determination to kill. Meaning The findings are foundational to the debate over whether deadly weapons should be better regulated and provide evidence against the common view that whether the victim lives or dies is determined largely by the assailant’s intent and not the type of weapon.

Why do gun murders have a higher clearance rate than gunshot assaults?

“…In effect, the fatalities would be drawn from an urn and, for a large sample, would tend to be similar to the universe of all gunshot cases. But in reality we expect some differentiation among cases, certainly with respect to such immediate factors as the number of shots fired, the caliber of the gun, the skill of the shooter, whether the shooter was in control of the situation, and so forth (Braga & Cook, ). In that sense, the average ex ante probability of the fatal cases would be higher than the average for the nonfatal cases.…”

“…For the variables included, there is no discernible difference, with one exception-fatal shootings are significantly more likely to occur indoors (23% vs. 14%). The importance of the "similarity" finding is that it can be used by researchers to help establish the claim that any difference in clearance rates is not a result of the variables considered here (see also Braga & Cook, 2018).…”

Thinking about gun violence

“…We limited the analysis to handguns, since use of rifles or shotguns is very rare in Boston criminal assault. The caliber of handgun was not correlated with any observable feature of the attack, but it had a close association with the principal outcome—whether the victim lived or died (Braga & Cook 2018). One way to summarize our results is this: If all criminal shootings in Boston had been with the smallest common caliber (.22), rather than the actual mix that was dominated by larger caliber handguns (.38 revolvers, 9 mm pistols, etc.…”

Understanding Gun Violence: Public Health vs. Public Policy

“…Viewed as an outcome, public health metrics also help illuminate why gun use in violence is a problem warranting public attention. One of the primary justifications for a distinct focus on guns is that the case‐fatality rate for gunshot wounds is far higher than for wounds inflicted with other commonly used weapons, for both assaults and suicide attempts (Braga & Cook, ; Miller et al., ; Zimring, ). Thus, separating guns from violence can have a powerful mitigation effect on violence.…”