Law & Order: Criminal Intent Season 2 Episode 22

Part 1 of 2: The murder of a crooked cop puts Detectives Goren and Eames on the trail of an obsessively clean doctor whose previous girlfriends all seem to be afflicted with a "zoonotic" disease -- or a virus found only in animals. Their probe also points to a preening veterinarian as well as a looming psychological component that is crucial to putting a bulletproof case together.