Undoubtedly, the gang influence that has most affected communities, far and wide, across the United States has been Chicago based gangs. In this regard, two "real cops" that have affected the professional lives of gang investigators across the United States came together to write a book about these Chicago based gangs. Retired Chicago PD Gang Detective, Joe Sparks and King County, WA, Gang Specialist Gabe Morales are not only two of the most experienced gang investigators I have ever met, they have assisted me in many of my own gang investigations. They have also assisted many other gang investigators across the country. Joe and Gabe have always gratefully offered to share their knowledge, expertise, and precious time with other cops. They have always gone beyond their call of duty and have helped countless cops and communities understand and fight the scourge of gangs because they understand it helps us all to be safer. - Lou Savelli, Ret. Gang Sgt. NYPD