Herbert Beigel was an attorney in the Chicago Strike Force--a division of the Organized Crime section of the Justice Department--when, in 1970, his office hunched an investigation of police corruption in Chicago. The investigation inched along for six years, and eventually some 70 police officers were indicted for shakedowns of taverns in two of the city's 23 police districts--the 15th and the 18th. While the story of the ""$100-a-month club"" and the organized hierarchy of on-the-pad cops never acquired the glamor of the Knapp Commission's sensational revelations about New York, there are many parallels. The special investigators ran into the same stonewalling and conspiracy of silence within the P.D.; the chief breeding ground of corruption was the vice squad; and ""victimless"" crimes such as gambling and prostitution were the most lucrative for cops. Finally, as Beigel glumly points out, the investigation scratched only the barest surface--no reason to think the other 21 districts were any purer. Though a worthy report on official malfeasance and the laborious work of those charged with rooting it out (corruption is built into the institutional set-up, not the result of ""bad apples,"" Beigel argues), this is a discouragingly difficult book to read. The Beigels require an introductory cast of characters and an organizational chart of the Chicago police department before they can begin the tangled story, and the prose is even less sparkling than the average legal brief or police dossier. For those with a sustained interest in the subject who don't ask for pyrotechnics.