The New York Times and the Marshall Project report that homicides are much more likely to be ruled justifiable when a black man is killed by a white person. Racial disparities in self-defense is a topic I’ve spent a fair amount of time thinking about, because in 2013 I had a challenging and rewarding back-and-forth about it with John K. Roman and Shebani Rao of the Urban Institute. (Roman’s study, my response, their reply, my final comment.) There may be some bias in these decisions, but I don’t think this kind of statistic is very helpful when it comes to studying it.
Basically, when a member of one group attacks a member of another group, two things can happen that will affect homicide statistics: The aggressor can kill the victim, or the victim can kill the aggressor. The former act should be charged as a crime, the latter ruled justifiable (assuming the victim reasonably feared for life or limb). Therefore, more acts of aggression by members of a group translate to more unjustifiable homicides for that group and more justifiable homicides for the other group. As a result, if one group commits more violent crime, we’d expect that group’s homicides to be justified a lower percentage of the time.
You can follow the links above for more details on the math, but using a victimization survey by the Justice Department (which avoids the issue of racial bias in arrest statistics), a rough estimate is that there are 767,000 acts of black-on-white violence and 128,000 violent acts where the races were flipped in the U.S. annually. As I explained, if 2 percent of all victims of violence defend themselves,
128,000 acts of white-on-black violence inspire 2,500 acts of justified violence by blacks. And 767,000 acts of black-on-white violence inspire 15,000 acts of justifiable violence by whites. . . . As a result, 10 percent of white-on-black violence is justified, and only 0.3 percent of black-on-white violence is. This corresponds closely to the actual disparity from the FBI figures [regarding homicides ruled justifiable]: 11.41 percent to 1.2 percent.
I also pointed out that most justifiable homicides involve guns, and that whites report owning guns at about twice the rate of blacks.
The NYT/Marshall analysis does adjust the data to account for numerous factors, such as the relationship between the parties, the killer’s sex, the broad type of confrontation, and the weapon used, and finds that the disparity falls from to eight times to 4.7 times. But they don’t have a way of figuring out which party was actually the aggressor, and therefore they can’t tell whether prosecutors make the wrong decisions, letting off whites and/or prosecuting blacks in cases where they’d have done differently if the races were reversed. (I also find it frustrating that in most of their statistics they compare overall rates with rates for black men, combining sex and race so it’s hard to tell the role of each factor. Anyone want to guess whether man-on-woman or woman-on-man homicides are more likely to be self-defense?)
Again, I’m not claiming there’s zero bias at play here; the data are murky enough that we can’t know for sure. But the disparity documented in the report isn’t evidence of bias. It’s exactly what we’d expect to see when one group offends at a higher rate than another.