Declan McCullagh's politechbot has a posting suggesting that BTK serial killer case may have been cracked by covertly acquiring a tissue sample for DNA testing:
Cops covertly acquired tissue of BTK suspect's relative -- from medical lab [Politech]:
"In developments straight out of GATTACA's handshake scene, A Kansas City Star report indicates that the suspected 'BTK' killer was tentatively linked to crime scene evidence by acquiring genetic material from the suspect's daughter's medical records - the tissue samples being taken without her knowledge.
The article goes on to give a brief but factually accurate explanation of how a request for 'medical records' is entirely within the framework of the federal medical privacy laws (HIPAA), and also gives a likely source of the tissue - a routine pap smear. The article suggests that a judge issued a secret order for the records, though the article does not state if it was a formal 4th Amendment 'probable cause' warrant, or some lesser standard subpoena, or even go into whether the police were required to acquire an order under HIPAA (there are circumstances where agents can just the recordholder.)..."
Thanks to Rob Hyndman for the pointer.