This report is one of a series of five describing a 16-month study of the nature and extent of the private police industry in the United States, its problems, its present regulation, and how the law impinges on it. A general discussion of the sources of legal limitations upon private police activities and personnel and sources of legal powers is included, in addition to an examination of specific legal problems raised by these activities and by the relationships between the users and providers of private security services. The legal doctrines governing particular security activities are evaluated and recommendations for improvement are presented. Documents in the series are announced in this issue as VT 016 622-VT 016 626. (AG)