In San Francisco our black population has been shrinking as blacks have left in large numbers over the past half-century.
Because the black neighborhoods are dangerous, gentrification is slow. Except for the areas where Redevelopment tore-down black neighborhoods and sold the re-built properties to blacks there is a very different pattern in the untouched black ghettoes.
When the market takes its appropriate role, old black neighborhoods are gentrified by Asians. Particularly by Filipinos and Chinese.
It seems to me that the reason these two groups are the ones who are buying formally black neighborhoods is that prices are low and neither the Filipinos nor the Chinese seem to be regular targets for black criminals. Their targets seem to be other blacks, Latinos and whites.
Just my observations. If you have a black population that is troublesome you might consider inviting more Filipinos and Chinese to your community. You could expect gentrification of the black neighborhoods in very few years.