The alleged epidemic of police brutality against black bodies sweeping through the nation's urban cores aside, the tendency for blacks not to cooperate with the cops is nothing new.
In the 1984 iteration of the survey, the GSS asked respondents if they would feel obligated to report a crime they witnessed occurring.
The percentages, by race, who felt doing so to be "very important" (n = 1,442):
White -- 91.6%
Black -- 77.9%
Other -- 86.9%
One of the many reasons unsolved murders are disproportionately black murders.
GSS variables used: OB911, RACE