From the Federal definition of a gang: An association of three or more individuals whose members collectively identify themselves by adopting a group identity, and whose purpose in part is to engage in criminal activity.
The association may also possess some of the following characteristics: 1. The members may employ rules for joining and operating within the association. 2. The members may meet on a recurring basis. 3. The association may seek to exercise control over a particular geographic location or region. 4. The association may have an identifiable structure.