I read that the crime statistics (including murder) for blacks before the mid 1970's were very unreliable. That the police would record a likely murder of black citizen as death from natural causes to avoid paperwork.
According to Thaddeus Russel who studies vice, majority black areas were lightly policed and that was one of the reasons that the black caucus pushed the way Jason said they did.
That would undermine the story that the black crime rate was lower. On the other hand if Thaddeus is correct but police properly recorded the great majority or murders correctly them maybe defunding police would not result in a large (say up 50%) increase in murder.
Is there proof either way?