Books: I checked out "Gloria & Office Buckle" by Peggy Rathmann and some nonfiction books about police officers.
http://www.first-school.ws/activities/commhelper/policeofficer.htm Badge & Hat
Make a simple police vest using a large paper grocery bag. With the bag opened, make a large round opening on the bottom for the head and cut the bag open along the front. Make round holes on the sides for arm holes. Close and lay the bag flat and children can paint the front using tempera paint and using a sponge. Cut a long strip of black construction paper to form a belt - just for the front where is painted, and glue on bag when the paint is dry. Attach the badge and the vest is ready to wear.
http://www.sandiego.gov/police/prevention/crimeprev/cpbook.pdf McGruff safety