The Cuckoo's Calling by Robert Galbraith aka J K Rowling (2013) Mulholland Books 

Cormorant Strike, a disabled British veteran MP is now a private detective with a ruined love life, enough bills to sink his business and a new temp receptionist.  He’s also the son of a rock star.  A client wants him to find the murderer of their famous model sister, whom has been ruled a suicide.