Source: Rose, H. M. & MacClain, P. D. (1990). Race, Place, and Risk: Black Homicide in Urban America.  New York, NY: SUNY Press.

Homicides in Detroit peaked in 1974 with 750 murders recorded. Between 1965 and 1970, violent crime had doubled. The auto industry was in decline and 100,000 manufacturing jobs had left the city. This economic loss was paired with flight of white residents and the introduction of heroine. Many unemployed black workers turned to the drug trade for both income and relief from depression.