By LINDA GREENHOUSE
WASHINGTON, June 11 In an important declaration of the
constitutional limits on new privacy- threatening technology, the
Supreme Court ruled today that the use by the police of a thermal
imaging device to detect patterns of heat coming from a private home is
a search that requires a warrant.
The court said further that the warrant requirement would apply not
only to the relatively crude device at issue but also to any "more
sophisticated systems" in use or in development that let the police
gain knowledge that in the past would have been impossible without a
physical entry into the home.
"We must take the long view, from the original meaning of the
Fourth Amendment forward," Justice Antonin Scalia wrote for a
5-to-4 majority that cut across the court's usual ideological division.
[Excerpts, Page A29.]
Justice Scalia said that to take any other approach "would leave
the homeowner at the mercy of advancing technology including imaging
technology that could discern all human activity in the home."
The decision overturned a ruling by the United States Court of
Appeals for the Ninth Circuit in San Francisco often regarded as the
most liberal of the federal appeals courts which held in 1999 that
the warrantless use of a device that revealed patterns of heat
suggestive of an indoor marijuana-growing operation did not violate the
Fourth Amendment's prohibition of unreasonable searches.
In a dissenting opinion today, Justice John Paul Stevens who in
turn is usually described as the court's most liberal justice said
the Ninth Circuit was correct and that the police activity in the case
"did not invade any constitutionally protected interest in
privacy." He said that for the court today to make a constitutional
rule about future technology was "unnecessary, unwise and
inconsistent with the Fourth Amendment."
Those who joined Justice Scalia in the majority were Justices David
H. Souter, Clarence Thomas, Ruth Bader Ginsburg and Stephen G. Breyer.
Chief Justice William H. Rehnquist joined the dissent, as did Justices
Sandra Day O'Connor and Anthony M. Kennedy.
The case, Kyllo v. United States, No. 99-8508, was a federal drug
prosecution that began in 1992, when two federal agents trained a device
called Agema Thermovision 210 on a home in Florence, Ore., where, on the
basis of tips and utility bills, they believed marijuana was being grown
under high-intensity lamps. While the imager cannot see through walls,
it can detect hot spots, and in this case disclosed that part of the
roof and a side wall were warmer than the rest of the building and the
The agents used that information to get a warrant to enter and search
the home, where they found more than 100 marijuana plants growing under
halide lights. The resident, Danny Kyllo, entered a conditional guilty
plea while continuing to contest the validity of the search. He served
one month in jail.
When Mr. Kyllo's Supreme Court appeal was argued in February, the
government strongly defended use of thermal imagers on the ground that
in detecting heat loss, the devices neither reveal private information
nor violate the "reasonable expectation of privacy" that is
the Supreme Court's test under the Fourth Amendment.
But in the home, Justice Scalia said today "all details are
intimate details, because the entire area is held safe from prying
government eyes." Noting that the court's precedents draw "a
firm line at the entrance to the house," he added, "That line,
we think, must be not only firm but also bright."
Despite its forceful language, the decision was undoubtedly not the
court's final word on the subject of privacy and technology. Justice
Scalia's emphasis on the home raised the prospect that warrantless
imaging of other locations might be upheld. And it is far from clear
under the court's precedents that a person in a home that belonged to
someone else would have standing to challenge the use of an imager.
Further, the majority limited its holding to devices that are
"not in general public use," without explaining that
limitation. In his dissenting opinion, Justice Stevens said this
limitation was "somewhat perverse because it seems likely that the
threat to privacy will grow, rather than recede, as the use of intrusive
equipment becomes more readily available."
Nonetheless, the decision was important and "surprisingly
broad," said James J. Tomkovicz, a law professor at the University
of Iowa who filed a brief for the National Association of Criminal
Defense Lawyers and the American Civil Liberties Union.
"It was important for the court to say that there are general
limits on the ability of technological developments to erode Fourth
Amendment privacy," he said in an interview.
The vote today underscored the unpredictable, if not incoherent,
nature of the court's rulings on the Fourth Amendment, currently an
extremely active area of the court's jurisdiction. Last year, for
example, the court ruled that police officers had conducted an
unconstitutional search when they walked down the aisle of a
long-distance bus and squeezed passengers' overhead luggage to look for
contraband. Chief Justice Rehnquist wrote the 7-to-2 opinion in that
case, Bond v. United States, while Justices Scalia and Breyer dissented.
On display today was Justice Scalia's insistence that the Fourth
Amendment be interpreted according to the understanding of its framers.
Requiring a warrant to use technology that displaces an old-fashioned
search "assures preservation of that degree of privacy against
government that existed when the Fourth Amendment was adopted,"
Justice Scalia said.
For Justice Stevens, on the other hand, the problem with the majority
opinion appeared to be its sweeping nature.
In crafting "an all-encompassing rule for the future,"
Justice Stevens said, the court "has unfortunately failed to heed
the tried and true counsel of judicial restraint." He added,
"It would be far wiser to give legislators an unimpeded opportunity
to grapple with these emerging issues rather than to shackle them with
prematurely devised constitutional constraints."