Key points are not available for this paper at this time.
Pamela Irving Jackson, Leo Carroll, Race and the War on Crime: The Sociopolitical Determinants of Municipal Police Expenditures in 90 non-Southern U.S. Cities, American Sociological Review, Vol. 46, No. 3 (Jun., 1981), pp. 290-305
Jackson et al. (Mon,) studied this question.