@Cafe41 -I know what you mean but my favorite true detective stories were written by Nicolas Pileggi. He wrote a number of New York Times bestseller relating to real life detective stories such as “Wise Guys”, and “Casino”.
Both of these books were turned into motion pictures and both dealt with the Mafia. Peter Maas also wrote books of the same vain and his most famous books were “Valachi Papers” also depicting the Mafia families and “Serpico” which was made into a film starring Al Pacino.
Serpico was a true story about a New York detective and how he could not succumb to corruption like many of those police officers around him. These stories are really gritty but once you start reading these books it is hard to put them down.