From the Roaring Twenties to the 1970s detectives reigned supreme in police departments across the country. In this tightly woven slice of true crime reportage, Thomas A. Reppetto offers a behind-the-scenes look into some of the most notable investigations to occur during the golden age of the detective in American criminal justice.

From William Burns, who during his heyday was known as America’s Sherlock Holmes, to Thad Brown, who probed the notorious Black Dahlia murder in Los Angeles, to Elliott Ness, who cleaned up the Cleveland police but failed to capture the “Mad Butcher” who decapitated at least a dozen victims, American Detective offers an indelible portrait of the famous sleuths and investigators who played a major role in cracking some of the most notorious criminal cases in U.S. history. Along the way Reppetto takes us deep inside the detective bureaus that were once the nerve centers behind crime-fighting on the streets of America’s great cities, including the FBI itself, under the direction of America’s “top cop,” J. Edgar Hoover.

According to Reppetto, detectives were once able watchdogs until their role in policing became diluted by patrol strategies ranging from “stop and frisk” to community policing. Reppetto argues against these current policing systems and calls for a return to the primacy of the detective in criminal investigations.