There are 4 books in the Detectives Frolich and Gunnarstranda series.
The Detectives Frolich and Gunnarstranda series does not have a new book coming out soon. The latest book, Lethal Investments (Book 4), was published in December 2012.
The first book in the Detectives Frolich and Gunnarstranda series, The Fourth Man, was published in March 2008.
The Detectives Frolich and Gunnarstranda series primarily falls into the Police Procedural genre.