A new Texas A&M study indicates that “castle laws” intensify violence rather than accomplish their intended purpose, which is to deter crime.
College Station-based economics professor Mark Hoekstra conducted an empirical study using statewide crime data from 2000-2009 FBI Uniform Crime Reports and compared the states with castle laws against the crime rates of “non-adopting states over the same period.” Hoekstra and his graduate student Cheng Cheng found evidence that up to fifty “additional justifiable homicides” occur per year as a result of “castle” doctrine. Justifiable homicide is defined as “the killing of a felon, during the commission of a felony, by a private citizen.” In states without castle laws, homicide rates stayed the same over time. The results of the study are pretty damning for proponents of the castle laws:
We find no evidence of deterrence; burglary, robbery, and aggravated assault are unaffected by the laws. On the other hand, we find that murder and non-negligent manslaughter are increased by 7 to 9 percent. This could represent either increased use of lethal force in self-defense situations, or the escalation of violence in otherwise non-lethal situations. Regardless, the results indicate that a primary consequence of strengthening self-defense law is increased homicide.
“Our study makes no judgement as to whether these laws are in some sense good or bad. Rather, the main finding is that the laws result in more homicides,” Hoekstra said.