Here’s a general outline of the rankings of these departments: Law enforcement Ranks: A law enforcement commissioner is usually the highest ranking officer in a metropolitan law enforcement force, overseeing all of the other departments.In some cities, the law enforcement commissioner isn’t a uniformed officer and is appointed by the city’s mayor. law enforcement officer is the lowest member of the law enforcement ranks totem pole, although there are usually several different pay grades within the ranking. To move up the ladder from an officer to a captain involves taking examinations, as well as completing a certain amount of time in each rank.