Which is NOT a recognized type of gang?

The correct answer identifies "Professional Gangs" as not being a recognized type of gang within the context of criminal and gang studies. Traditional gangs, white supremacist gangs, and prison gangs are well-documented categories that represent specific characteristics, motivations, and structures within gang culture.

Traditional gangs are typically rooted in specific neighborhoods and have an established presence, often engaging in various criminal activities and working to maintain territorial control. White supremacist gangs focus on ideologies of racial superiority and often engage in hate crimes and violence based on their beliefs. Prison gangs, formed within the correctional system, operate based on a hierarchy and often engage in criminal activities both inside and outside of prison walls, maintaining influence even after members are released.

In contrast, while one might find groups that operate professionally in criminal enterprises, the term "professional gangs" does not align with the established typologies recognized in gang studies and law enforcement contexts. Hence, it does not serve as a category for group identification, making it the correct answer in identifying something that does not fit within recognized gang classifications.