UNREASONABLE SEARCH: HIGH COURT SAYS NO TO TECHNOLOGY

Washington --- Hard cases, they say, make bad law. The case of Danny Kyllo
was a hard case. On June 11, sure enough, the Supreme Court made some bad
law out of it.

The facts were never at issue. Federal agents in Florence, Ore., received
tips that Kyllo was growing marijuana in his home. A check of his utility
bills added to their suspicion. The officers doubted they had enough
evidence to obtain a search warrant, so they resorted to a thermal imager.

They set up the device in a car across the street, and at 3:20 on a morning
in January 1992 the instrument recorded a high level of heat radiating from
the garage roof.

Armed with this information, the federal agents obtained a warrant to
search Kyllo's home. There they found more than 100 marijuana plants, their
luxuriant growth promoted by the warmth of high-intensity halide lights.
Kyllo moved to suppress the thermal evidence, but eventually his motion was
denied. He appealed, and the Supreme Court agreed to decide whether thermal
imaging violates the Fourth Amendment.

The Fourth Amendment says that the government may not violate the right of
the people to be secure in their houses against unreasonable searches. The
question before the high court was deceptively simple: Was the thermal
imaging a search, and was it unreasonable?

The high court ruled 5-4 that yes, the agents' conduct constituted an
unreasonable search. The government may put Kyllo on trial again, but
without the agents' evidence the government has no case.

Justice Antonin Scalia wrote the majority opinion. He is the court's most
gifted jurist, but this was not his best effort. He concluded that the
federal agents crossed a forbidden line when they turned on the thermal imager.

This was his key sentence: "We think that obtaining by sense-enhancing
technology any information regarding the interior of the home that could
not otherwise have been obtained without physical intrusion into a
constitutionally protected area constitutes a search --- at least where (as
here) the technology in question is not in general public use." It was a
clumsy sentence, the product of clumsy thought.

More than 70 years ago, in the landmark case of Olmstead v. United States,
the court first wrestled with the Fourth Amendment problem of
"sense-enhancing technology." In 1928 this was wiretapping. The offense was
bootlegging.

The court voted 5-4 to let Olmstead's conviction stand. There had been no
physical intrusion into the defendant's home; the intercepted conversations
were not tangible; and the Fourth Amendment does not protect intangible things.

The court ditched the reasoning of Olmstead in Katz v. United States in
1967. The case involved a professional gambler who used a sidewalk
telephone booth to talk with his clientele. Police eavesdropped with an
electronic device placed outside the booth. The court ruled 7-1 that the
government had thus violated Katz's reasonable expectation of privacy. The
evidence was thrown out.

Since then the court repeatedly has grappled with "sense-enhancing
technology. Lawyers, laymen and lower courts find the confusion compounded.

It is OK for police to use a pen register at the telephone company to
determine the numbers dialed from a private home. It is OK to admit
evidence derived from a low-flying airplane. It is OK to enhance the human
eye with binoculars and telescopes. It is OK to use trained dogs to sniff
for illicit drugs.

Suddenly we are thrown back to Katz. Now it is not OK, without a warrant,
to use the technology of a thermal imager.

Scalia, for his part, worried that without a bright line, homeowners could
be left at the mercy of advancing technology. The "relatively crude" device
used in the Kyllo case could disclose "at what hour each night the lady of
the house takes her daily sauna and bath." The court's new rule is intended
"to take account of more sophisticated systems that are already in use or
in development."

It is an old rule that fire is sometimes best fought with fire. In a world
of criminals who present dangers far more serious than Kyllo's attic
plantation, detectives have to have some freedom to detect.