Some of these people dealt with an individual who wrote a document to (*)
The cunning Jonathan Wild amassed a fortune by posing as people in this profession. The law organizing the modern body of this profession replaced the Statute of Winchester. The organizer of the modern incarnation of this profession in Britain stated that "[they] are the public and the public are [them]" as part of Nine Principals. An early organization of this profession was led by Henry Fielding and was called the Bow Street Runners. Some of these people dealt with an individual who wrote a document to (*) Mr. Lusk called the "From Hell" letter after a series of events in the Whitechapel District. Some members of this profession were called "Bobbies" or alternately "Peelers," because they were organized in London by Robert Peel. For 10 points, give this profession of people at Scotland Yard. 
The cunning Jonathan Wild amassed a fortune by posing as people in this profession.
policemen [or watchmen; constables; thief-takers; detectives; accept other synonyms] 