O'Brien has also written seven detective novels: Close-Up on Death (1989), Deadly Reflection (1993), Mask of Betrayal (1998), Dead Innocent (1999), Revenge (2001), Unauthorised Departure (2003) and Every Step You Take (2004); all feature the character of Detective Inspector John Bright.
O'Brien yedi adet dedektif romanı yazmıştır: Close-Up on Death (1989), Deadly Reflection (1993), Mask of Betrayal (1998), Dead Innocent (1999), Revenge (2001) Unauthorised Departure (2003) ve Every Step You Take (2004); Romanlarının hepsinde Dedektif Müfettiş John Bright karakterine yer vermiştir.