The datum: "That shit happens all the time." In "The Police as Perceived by Negro Boys", ed. Carl Werthman; in The American City: A Source Book of Urban Imagery, edited by Anselm L. Strauss (Chicago: Aldine, 1968), p. 285. Here in Google Books. A footnote says that Werthman's short contribution to the book is "Excerpted from 'Gang members and the police', unpublished M.A. thesis, University of California, Berkeley, 1964."