An introduction describes the study and discusses file structure, processing information, and codebook information. The time series data for the 23 cities came from police annual reports found in the Library of Congress or in newspapers and legislative reports located elsewhere. Variables in the raw data file include arrests for drunkenness, conditional offenses, and homicides; persons dismissed or held; police personnel; and population. The second file aggregates by year and reports some of these variables on a per capita basis using a linear interpolation from the last decadal census to estimate population. (Author summary modified)