The study identified three subgroups that were receiving services from street workers: “full migrants” (subjects and parents both outside Germany), “partial migrants” (subjects and/or one or both of their parents born outside Germany), and “nonmigrants” (youth and parents born in Germany). Both migrant subgroups exhibited more problems in some life and behavioral fields than did the nonmigrant subgroup (e.g., less communication with parents, less time reading, and more time playing video games). Unexpectedly, the “full migrants” were not always worse off. On the contrary, for some critical issues, the “partial migrants” dominated the relevant percentages, particularly regarding individual delinquency involvement and other troubles. This study did not provide enough specific data in order to determine the factors that lead juveniles in Germany to join troublesome youth groups; however, some significant deficits in interpersonal relations and the need for identity and status seem to be factors. For some 74 percent of the juveniles who belonged to the criminally active subgroup, “feeling important” was a major factor. The study, which was conducted between November 2004 and December 2005, recruited the study sample from three districts in Stuttgart regarded by the Mobile Youth Work team as “typical” of various problem profiles in the city. Approximately 200 youth were contacted either in or through neighborhood youth clubs operated by the Mobile Youth Work teams. Eventually, 157 youth consented to participate in the study and completed questionnaires. This chapter deals only with data related to the youths’ deviant and delinquent behavior linked to family factors, personal characteristics, and their joining of troublesome youth groups. 6 tables and 41 references