Most gangs are found within cities that contain pockets of segregated people. The Spanish or Mexican American brown gangs of the Southwest typically live in a common neighborhood and attend a common school. Members are recruited when they are 10 or 11, often through physical intimidation. A new member joins a clique composed of boys his approximate age and then undergoes a test to prove his manhood and courage. Brown gang members dress in a particular manner and use a language called 'calo.' Black gangs usually require a criminal act before membership and are broken down into sets determined by area as well as age. Blacks also have their own language, 'smack,' and manner of dress. Asian gang members tend to be older than black or brown gangs and more secretive about membership. They apparently are financed by older well-established Asian gangs. Motorcycle gangs, the most common Caucasian gang, tend to avoid police officers and are involved in drug trafficking and organized crime. They are very ritualistic, well-armed, and well-organized for any criminal activity. Street officers should consider what motivates gangs, keeping detailed records and learning their habits and some of their slang. Careful display of information known about a gang creates a degree of respect for the officer. Police should not promise things they have no intention of doing, not favor one gang over another, and not play one against the other in conversation. In investigating gang crime, an officer can patiently make frequent contacts with victims and possible witnesses to gain their confidence or simply exchange a weak prosecution case for return of the stolen items. The article contains eight footnotes.