Drug-testing cities through their sewage.

Jurors acquitted a man of rape on the grounds that "sexsomnia" made him do it. Circumstances: He, the 15-year-old victim, and others went to sleep separately after a drunken house party. She woke up to find him on top of her, naked. His defense: "I laid down to go to sleep. The next thing I knew I was … completely naked in the middle of the street." Hypothesis: Sexsomnia, a disorder that "causes people to commit sex acts in their sleep." Evidence: 1) His fellow soldiers had nicknamed him "Night Rider" because he walked in his sleep. 2) His girlfriend says he previously "fondled her in bed while asleep." 3) He allegedly "had once punched his girlfriend during a bad dream, but had no recollection of it. " Number of women on the jury: five. Deliberation time: two hours. Skeptical views: 1) "I would think it was extremely difficult to perform such a complex maneuver as having sexual intercourse while asleep—especially if the other person is unwilling." 2) "There are a lot more people who will get off lightly using the same defense." (To comment, join the Fray.)

Latest Human Nature columns:  1) The jihad against tobacco. 2)  Fat lies and fat lies revisited. 3)  Liberals and bioethics. 4) The case for turning food into fuel. 5) Recombining  man and beast. 6) The spread of virgin births. 7) Abolishing menstruation. 8) The chess match of man and machine. 9)  Ultrasound and the future of abortion.