It is the goal of many a modern mystery writer to merge sadism with sociology. If you unleash a serial killer to prey on the young and vulnerable, you'd better add something -- a sermon about society's ills, keen human insight -- so that your movie (The Silence of the Lambs), novel (The Alienist) or TV series doesn't appear irredeemably sordid. If it is done right, author and audience can enjoy the best of both worlds: luridness without guilt.
In Prime Suspect 3, a four-part British mini-series that begins Thursday on PBS' Mystery!, the murder scene is London's gay underground of...