Pertinent quote from the results section of the publication:
Most people who come from a socio-economically less favorable background do not commit more crime than people who come from a more favorable background, and it also happens that people from a more favorable background do commit crime. This means that even if there is a connection between socio-economic background and involvement in crime, that connection is weak. It is not possible to appreciably predict who will commit crimes based on knowledge of people's socio-economic background.
https://bra.se/publikationer/arkiv/publikationer/2023-03-01-socioekonomisk-bakgrund-och-brott.html
I believe it comes down to generational wealth. My grandparents were solidly middle class for their time, which meant they had some savings for retirement. When my mother made a mistake and got pregnant as a single mother, they bent over backwards to put me in good schools and keep me doing the right thing.
If I were to repeat that mistake, my mother would be completely incapable of helping me in the same way, and my kids would have a much harder road of it.
Black Americans, simply put, never had that sort of generational nest egg to fall back on. By my calculations this is going to get worse before it gets better, and we'll see violent (feral, honestly) behavior across all races.
Lol. The most funded schools are in black ghetto neighborhoods. The students make the school. The school does not make the students. Schools are not a substitute for parenting.