Bike gangs, which emerged in the early 1950's as loosely knit rowdy groups, had become well established by the early 1960's and are now recognized as dangerous criminal groups; however, they compose only 1 percent of the Nation's bikers, according to statistics compiled by the American Motorcycle Association. Currently, there are several thousand outlaw motorcyclists residing in virtually every State, and they are organized into some 900 dangerous clubs. The biker gangs typically have a national president, territorial or regional representatives, a national secretary-treasurer, a national enforcer, chapter presidents, vice presidents, secretary-treasurers, sergeants at arms, road captains, members, probate or prospective members, associates or honorary members, and a constitution or by-laws. Gangs' basic philosophy is to challenge all symbols and lifestyles of normative society and find acceptance and meaning in club activities and social interaction. Clubs hold to a philosophy of white supremacy. Criminal activities of the gangs include illegal weapons offenses, the investment of criminal profits in legitimate businesses, drug trafficking, murder, rape, assault, burglary, prostitution, and the intimidation of citizens and witnesses. This booklet includes an outline of investigative techniques for biker gangs and a glossary of terminology.