Michigan Dept. of State Police v. Sitz 496 U.S. 444, 110 S. Ct. 2481, 110 L. Ed.2d 412 (1990)
The police in Michigan set up
a sobriety checkpoint. They pulled over random vehicles without suspicion
and checked to see if the drivers were drunk.
A group of Michigan residents
(led by Sitz) sued for an injunction to stop the practice.
Sitz argued that the
suspicionless searches were an unreasonable invasion of privacy under the
Michigan Constitution and the 4th Amendment.
The Trial Court found for the
police and did not issue the injunction. Sitz appealed.
The Trial Court performed a
balancing test and found that the State's interest in keeping drunks off
the roads, and the effectiveness of the program outweighed the minor
inconvenience to the drivers.
See Brown v. Texas (443 U.S. 47 (1979)).
The Appellate Court reversed.
The police appealed.
The Appellate Court
performed the same balancing test, but found the program to be a
violation of the 4th Amendment.
The Appellate Court found
that while the State has an interest in keeping drunks of the roads, and
the inconvenience was minor, the program was not very effective. So, on
balance, it was impermissible.
On one night, the police
stopped 126 cars, and found only one drunk driver.
The US Supreme Court reversed
and found the checkpoints to be legal.
The US Supreme Court found
that the checkpoints were as effective as could be expected, and
therefore they were constitutional under the balancing test.
"No one can seriously
dispute the magnitude of the drunken driving problem or the States'
interest in eradicating it." The Court then found that "the
weight bearing on the other scale...the measure of the intrusion on
motorists stopped briefly at sobriety checkpoints...is slight."
The Court compared this
case to their decision in United States v. Martinez-Fuerte (428 U.S. 453 (1976)), where a program to
catch illegal immigrants was found to be effective. That program was
less effective than the Michigan program was.
In a dissent it was argued
that Michigan (or any other State) could not show any decrease in drunk
driving accidents due to the start of sobriety checkpoints. Therefore
they were clearly ineffective and actually damaging because they took up
police time better spent doing other things. Therefore, they do not meet
the balancing test.
It was also argued that the
Court undervalued the personal privacy interest and overvalued the
State's interest.
In general, a suspicionless
search consisting of stopping people
at random, without individualized suspicion or probable cause can be considered constitutional as long as, on
balance, the government interest and the effectiveness of the program
outweigh the degree of intrusion into privacy.
Note that this only applies
to administrative searches, which
are done primarily for reasons other than criminal law enforcement.
In this case, the stops
were done to keep the roads safe, not to uncover criminal behavior.
See City of Indianapolis
v. Edmond (531 U.S. 32 (2000)).
One of the important factors
in an administrative search is that
it must be standardized and apply to everyone equally. Compare this case
to Delaware v. Prouse (440 U.S. 648 (1979)). In that case,
the police were stopping people at a checkpoint, but at the whim of the
policeman. In this case, the police were using an algorithm to pull
people over.
In order to be
constitutional, the search selection process must be non-discretionary.