This is the film Se7en, and here is a short summary:
Taking place in a nameless city, Se7en follows the story of two homicide detectives tracking down a sadistic serial killer who chooses his victims according to the seven deadly sins. Brad Pitt stars as Detective David Mills, a hopeful but naive rookie who finds himself partnered with veteran Detective William Somerset (Morgan Freeman). Together they trace the killers every step, witnessing the aftermath of his horrific crimes one by one as the victims pile up in rapid succession, all the while moving closer to a gruesome fate neither of them could have predicted.
I watched this film the other day, And I thought that it was gut wrenching and that the filmmakers stick to their vision with such dedication and persistence that something indelible comes across-something ethically and artistically superior to 'The Silence of the Lambs' that refuses to exploit suffering for fun or entertainment.