There are over 100 gangs in Chicago that have over 100 members. These gangs are from every community, and they are from every ethnic background. Regardless of how organized they are, criminal streetgangs opportunistically seek out new areas within which they can establish and expand their illegal operations. Some streetgangs are highly mobile and effectively networked, constantly mobilizing resources in their crime-motivated migrations to other communities. That is not to say that every gang is the result of an established gang's migration.
Some gangs develop on their own.
The best available social scientific studies of criminal streetgang activity have shown that while youth streetgang crime is a specialized form of delinquency, gang members are responsible for more crime and delinquency than their non-gang counterparts. Also important to note is that criminal streetgang activity is indefinitely variable, meaning that there is tremendous variation in both the number and type of specific criminal streetgang activities. Ominously, gang-related violent crime is growing by leaps and bounds even while the overall crime rate shows signs of stabilization. While Chicago's overall murder rate dropped slightly during the first eight months of 1996, gang-related homicides increased 24 percent during that same period. Gang Activity Development Cycle Streetgang membership, on the whole, is youthful.