Texas A&M Study Says Castle-Doctrine Laws Increase Homicides, Don't Deter Crime

[DanTex]

42. Sorry, you're wrong.

They measured self-defense using the FBI Uniform Crime Reporting's standard on justifiable homicides:

We use these data to test whether strengthening state self-defense laws does any of
three things. First, we ask whether these laws result in differential response on the part of
the civilians. To do so, we use data on justifiable homicide by private citizens, which is
defined as “the killing of a felon, during the commission of a felony, by a private citizen”
(Uniform Crime Reporting Handbook, 2004). A natural concern is whether reporting a
homicide as “justifiable” depends in part on the self-defense laws in the state at the time.
The FBI Uniform Crime Reporting Handbook makes it clear this should not be the case.
For example, the handbook emphasizes that “law enforcement agencies must report the
willful (nonnegligent) killing of one individual by another, not the criminal liability of the
person or persons involved” (Uniform Crime Reporting Handbook, 2004).

It is true that some of the increase in homicide is due to self-defense. But most of it is not. To be precise, the authors found that SYG resulted in 500-700 extra homicides, and only 50 extra justifiable homicides. They go on to point out that, even if you expand the definition of "self-defense" beyond the FBI classification, it is still unlikely that this would account for all of the increase, because killings classified as "murder" increased significantly, as well as those classified as manslaughter.

In the end, there is zero evidence to back your original claim that "it is likely" that the increase is due to criminals being killed.