The best source on the the cultural understandings of cops in America is in the work of Christopher P. Wilson, particularly his book Cop Knowledge and an article on Serpico and Prince of the City called "Undercover: White Ethnicity and Police Expose in the 1970s."

The Brookings Institution has released a new report, based on 2000-2008 census data, indicates that the suburbs are now the most likely location of the poor, and low-income ethno-racial minorities -- what an AP press story concludes is "white flight" in reverse.

http://www.google.com/hostednews/ap/article/ALeqM5hvFjjAiva42zBzRC8o2-s7zHD6IwD9FJ37800

http://www.brookings.edu/metro/MetroAmericaChapters/report_overview.aspx