By Michael Armstrong, Columbia University Press, 245 pages, $29.50

In the spring of 1970, the New York Times began publishing a series of reports of systemic corruption in the New York City Police Department based largely on information supplied by Frank Serpico, a Bronx plainclothesman, who outlined to the Times the pervasiveness of organized corruption at every level of the NYPD. Some of the corrupt cops were known as “meat eaters” and some as “grass eaters.” The former devoted portions of every working day to seeking out opportunities to “score,” for example, by stealing a portion of seized contraband or cash from drug dealers and gamblers; the latter were less driven than the “meat eaters” but accepted all gratuities in cash or goods that came their way in the course of a daily tour.