Summarize the definition of a gang used by the U.S. Department of Justice

First, summarize the definition of a gang used by the U.S. Department of Justice, and then invent a fictional character and explain at least 3 specific elements, known or unknown to him or her, that influenced his or her decision to join a gang. Consider their parental influences, community, home environment, school performance, and so on. Once these elements have been explained, address at least 1 myth related to gang activity.