An introduction explains that all law enforcement officers must exercise discretion throughout their careers since full enforcement of the laws is not practical and attainable and wide latitude exists for determining how laws are to be enforced. These materials, dating from 1932 through 1978, address this subject and such related issues as departmental guidelines, enforcement procedures, laws, and regulations. Emphasis is placed on evaluation, research, and future goals. The materials are intended to assist police agencies, law enforcement officers, attorneys, students, and researchers. Materials are listed alphabetically by author. Annotations are not included.