Book excerpt: Detroit's Infamous Purple Gang is a photographic history of one of the most notorious organized crime groups of the 20th century. The photographs chronologically follow the evolution of the Purples from their days as a juvenile street gang through their rise to power and eventual self-destruction. Using rare police department mug shots and group photographs, the book transports readers through the dark side of Prohibition-era Detroit history. Detroit had a gold rush atmosphere and a thriving black market during the 1920s that attracted gangsters and unsavory characters from all over the country.