Parenthetically, the correlation between a state's white and black offender rates is a statistically significant .52 (p = 0). Removing the low-end black offending states actually mitigates the relationship slightly to .48 (p = 0).
We've taken a look at white homicide rates by state. Now let's give black rates a gander. Using an online database out of the University of Michigan that utilizes the familiar SDA interface to pull figures from the Uniform Crime Reporting Data Series' homicide reports from 2009, 2007, 2006, 2005, and 2003 is how we'll go about it.
Murder rates among the total population are a lot easier to determine definitively than murder rates by subgroups within a population are. Murder is unlikely to go unreported--a corpse usually provides pretty good evidence of a homicide if it occurred. Take the number of murders by the overall population over a year and, voila, we have the homicide rate. However, the perpetrator(s) is sometimes unknown. Consequently, the sum rates of any number of non-overlapping subgroups is always going to fall short of the rate for the total population, even if the entire population falls into one of the various non-overlapping subgroups being considered.
To address this, for each state I figured the percentage of homicides perpetrated by blacks among those homicides for which the race of the killer was known and then assigned this percentage of the unknown perpetrator number to the black total. This assumes that the racial breakdown of unidentified murderers mirrors that of their identified brethren. Shows like CSI would have us believe that lots of the hard-to-catch killers are white. On the other hand, structural racism suggests that society often turns a blind eye to blacks killing blacks in the ghetto. Who knows? My guess is that this method understates the true black rates but that the effects of said understatements are pretty uniform across states.
Because 2006 is conveniently both the mean and median year employed, the black homicide rate per 100,000 people is calculated by averaging the number of murders in each state over the included five years and comparing it to a state's total black population in 2006. Both numerator and denominator include Hispanics who racially identify as black.
Only non-negligible homicides, which constitute the vast majority of all murders, are included.
Data are available from all states for each of the five years under consideration with the exception of DC (2009 data only) and Florida, which apparently doesn't participate in the UCR. Estimated black murder rates during the aughts per 100,000 blacks, by state:
|1. District of Columbia||38.68|
|19. West Virginia||19.70|
|22. New Jersey||18.19|
|25. South Carolina||16.64|
|28. New Mexico||16.00|
|29. North Carolina||15.40|
|32. New York||14.76|
|40. Rhode Island*||11.77|
|45. South Dakota*||8.69|
|46. North Dakota*||8.41|
|50. New Hampshire*||2.23|
An accompanying visualization is available here.
States without areas of high black population density generally appear to do the best. Mississippi is an impressive exception to that rule. If asked to take a stab at which American cities have the most dangerous black populations, I bet people answering candidly would heavily include Philadelphia, Milwaukee, and Detroit in their short-lists. Well, there you have it. I hear echoes of the unmentionable here, as well.