AS CRIME EBBS, TOP COURT'S PRIVACY RULINGS FLOW

In the clash at the Supreme Court last week between old-fashioned
personal privacy and newfangled law enforcement technology, few
people predicted privacy would be the clear-cut winner. But it turned
out that way when the court ruled that the police need a warrant to
aim a thermal imaging device at the outside of a house to look for
patterns of heat that could suggest indoor marijuana cultivation.

The ruling is the latest of several decisions suggesting that this
famously law-and-order court has begun to display a new skepticism
toward the arguments that police and prosecutors bring before it. And
the unanticipated shift is creating unusual alliances and
unpredictable outcomes.

The reasons for the subtle but perceptible shift are not immediately
obvious, given that there have been no personnel changes on the court
since 1994. But if the court's roster has not changed, the country
has; with violent crime at its lowest rate in 30 years, the national
conversation about crime is finding a new focus. It is almost as if
the public, liberated from the burdensome presence of crime, is free
to express doubts about the civic costs of a whole range of
crime-fighting strategies, from racial profiling to high-tech
eavesdropping to low-tech drug-sniffing dogs. Even capital punishment
is subject to greater debate now than at any time since the
mid-1970's.

"The country is nervous about privacy, about the discretion the
police exercise and the lengths to which they go," Barry Friedman, a
law professor at New York University who is studying the relationship
between the Supreme Court's behavior and public opinion, said in an
interview last week. "It's become a high-profile issue. Public
opinion doesn't escape the justices, and the court itself is starting
to get squeamish. On such a closely divided court, it doesn't take
much to turn them."

Indeed, last week's vote, in Kyllo v. United States, was 5 to 4. But
it was not the usual 5-to-4, conservative-liberal split. Justice
Antonin Scalia wrote the majority opinion in a case that conformed
neatly to his view that the Constitution should be interpreted
according to the intent of its framers; modern technology that
enables the police to gain knowledge that once would have
necessitated a physical entry into a private home, he said, requires
a warrant. Not to make that leap across time, Justice Scalia said,
"would leave the homeowner at the mercy of advancing technology."

Other cases this term also demonstrate the court's new concerns.
Defendants won two other cases that involved the Fourth Amendment's
prohibition on unreasonable searches and seizures. In a case from
Indianapolis, the justices ruled that police roadblocks where trained
dogs sniffed stopped cars to detect drugs were unconstitutional. In a
case from Charleston, S.C., the court ruled that hospital workers
could not test maternity patients for illegal drug use without their
consent and then turn over evidence of drug use to the police.

Prosecutors in both invoked the "special needs" doctrine the court
developed in the 1990's to uphold government drug testing programs to
argue that fighting the war on drugs justifies dispensing with the
amendment's usual requirements. But the court, in two 6-to-3
decisions, instead served notice that it was the doctrine, not the
amendment, that had limits.

Because law enforcement "always serves some broader social purpose or
objective," Justice John Paul Stevens said for the majority in the
Charleston case, a worthy goal was not a license to circumvent the
need for a warrant or at least suspicion of individual wrongdoing.

The exception this term was the Texas seat belt case, in which the
court ruled that the police had discretion to make a full custodial
arrest for a minor traffic offense, like not wearing a seat belt. The
surprise in this 5-to-4 decision was less the outcome than the
lineup, with Justice David H. Souter deserting his usual allies to
write the majority opinion and Justice Sandra Day O'Connor warning in
dissent that the decision carried "a grave potential for abuse."

ONE defense-oriented Fourth Amendment expert, Professor Tracey Maclin
of Boston University Law School, said the seat belt case was a
serious loss that outweighed the victories for defendants in the
other cases because once the police make an arrest, they can conduct
extensive searches. "What it means is that for the minorities and the
longhairs of the world, it's business as usual from this court," he
said.

The path through the tangled vines of Fourth Amendment doctrine has
never been straight or smooth. In three important Fourth Amendment
cases last term, the court gave similarly mixed messages. On the one
hand, it ruled that police officers conducted an unconstitutional
search when they walked down the aisle of a long-distance bus and
squeezed passengers' overhead luggage to feel for drugs. Chief
Justice William H. Rehnquist wrote that 7-to-2 majority opinion. The
court also ruled -- unanimously -- that an anonymous tip that a
person was carrying a gun was not, by itself, sufficient to justify a
stop-and-frisk search.

On the other hand, the court ruled that fleeing at the mere sight of
a police officer could be conduct suspicious enough to justify a
stop-and-frisk. The court was unanimous on that general rule, too,
though it divided 5 to 4 on its application to the particular case.

"It's refreshing that the court is not quite predictable these days,"
said another Fourth Amendment expert, Prof. James J. Tomkovicz of the
University of Iowa Law School, who filed a brief for the defendant in
the thermal imaging case. "Everyone is taking these cases one at a
time, trying to do what they think is right."

Among the recent cases, a consistent theme is a new sensitivity to
what Professor Tomkovicz called the "threshold" question. What is a
search? When does the Fourth Amendment begin to operate?

But more important than the details of any one case, he said, is the
court's message, both to the lower courts and to law enforcement
officials, "that there are constraints, that the Constitution is
alive and well."