Police Versus Private Detectives: Differing Investigations

Morel is le commissaire Martin Bataille

In The Body in the Library by Agatha Christie, a character points out that the trope smart detective outwits dumb police is an old-fashioned idea. And to her credit, Christie's novels, after the initial Poirot short stories, portray police officers as intelligent investigators who work alongside the P.I.  

A current approach to mysteries underscores this point. With Don Matteo, the first seasons revolve around the good priest solving the crime to the exasperation of Captain Anceschi and delight of Marshal Cecchini. But later seasons present Don Matteo and the police on parallel tracks. They arrive at the same conclusion at the same time if not through the same means or in the same way (or for the same purpose). 

The approach has its positives and negatives. On the positive side, it refrains from making the police look dumb. Even in Monk, the marvelous Ted Levine as Stottlemeyer sells the part through sheer force of personality. And his character admits that "these days," he spends a lot of time babysitting Monk. 

I also like the parallel approach for the philosophical implications--a crime CAN be solved in more than one way. Any crime will produce a score of potential clues and outcomes, all of which can be traced back to the perpetrator. 

On the downside, this approach separates the P.I. from the police. It is not quite as satisfying as watching them solve it together or watching the clever amateur detective produce THE vital clue. 

A show like Elementary manages to find the perfect balance. Sherlock and Joan do take their own approach, which often connects with and/or crosses over the police's approach. More importantly, although Sherlock and Joan have the epiphanies, they are often entirely reliant on the police investigation. THE vital clue, many times, actually comes from Marcus Bell.