What I’m saying is that yes, there exists a socioeconomic factor to crime, but that blacks always show a crime rate far above that of whites. So much so that even blacks in the top socioeconomic tier have a higher violent crime rate than whites in the very lowest tier, although they are gairly similar at those levels.
If you look at it on a chart, you can see that the black crime rates are constantly significantly above white levels for every socioeconomic tier.
Whether this is due to IQ or other genetic causes (e.g., MAOA-2), is not clear, but it’s clear that the crime differential is not due to socioeconomic causes, since whites are always at lower levels for every tier.
Separately, the average difference in IQ between American blacks and whites of about 15 points is well-researched and has been a constant for over a hundred years of measurement.