Heather Mac Donald offers a reason for the black-on-black murderfest in American cities.

"In every American city, the disproportionate black-illegitimacy rate is
matched only by the disproportionate black crime rate. In Chicago,
blacks, at least 35 percent of the population, commit 76 percent of all
homicides; whites, about 28 percent of the population, commit 4 percent.
In New York City, blacks, 24 percent of the population, commit 80
percent of all shootings; whites, 35 percent of the population, commit
less than 2 percent of all shootings. The black illegitimacy rate in New
York is over 78 percent; the white illegitimacy rate in the city is 7
percent. The national rate of homicide commission for black males
between the ages of 14 and 17 is ten times higher than that of “whites,”
into which category the federal government puts the vast majority of
Hispanics"

An article very much worth reading.