DUI Checkpoints in the Santa Clarita Valley
             Matthew Ruff, Top DUI Attorney in Santa Clarita, Call:  661-327-7833

Legal and Constitutional Issues Regarding Checkpoints:
Roadblocks and checkpoints are used quite frequently in then Santa Clarita Valley by the LASD and
CHP, respectively, to make temporary stops of drivers to check for alcohol consumption and misuse..
Municipal, county and state law enforcement divisions set up roadblocks and checkpoints for a variety
of reasons: checking the validity of driver’s license and registration; determining if the vehicle meets
safety inspection minimums; deciding if the car has the necessary municipal parking permit; etc. Used
with increasing frequency are checkpoints employed to apprehend intoxicated drivers.  

What is at issue in these scenarios? Checkpoints involve a constitutional detention, a seizure of a
person, without any level of particular, individualized doubt, i.e., reasonable suspicion or probable
cause. Since there is no focused suspicion on an individual, rather than assessing the existence or
absence of probable cause or reasonable suspicion, when the use of a roadblock is challenged, courts
will examine police conduct and the circumstances of the stop and determine if the checkpoint is a
reasonable intrusion, and therefore justifiable, under the Fourth Amendment. In the context of sobriety
checkpoints, this reasonableness determination involves an analysis of three factors: (i) the magnitude
of a state’s interest in preventing accidents caused by intoxicated drivers; (ii) the extent to which the
checkpoint advances that goal; and (iii) the measure of intrusion on an individual’s privacy, both
objectively, as perceived by the reviewing court, and subjectively, as the motorist may perceive the

The U.S. Supreme Court applied these factors to determine the constitutionality of a sobriety
checkpoint in Michigan Dep’t of State Police v. Sitz, 496 U.S. 444 (1990). Here, Michigan
implemented a program where checkpoints would be set up at predetermined sites along state roads.
All drivers passing through would be stopped and checked for obvious signs of intoxication. If such
indications were detected, the motorist would be taken out of the flow of traffic and an officer would
check his or her license and registration. If warranted, the officer would conduct field sobriety tests. All
other motorists would continue unimpeded after the initial screening. The check lasted 75 minutes,
during which 126 vehicles passed through. The average delay was 25 seconds. Three motorists were
detained on suspicion of intoxication, and two were arrested. The Court held that this checkpoint
passed constitutional muster. Citing the aforementioned factors, the Court found that:

(i) Michigan had a substantial interest in eliminating
drunken driving, noting that “no one can seriously
dispute the magnitude of the drunken driving problem [or the] State’s interest in eradicating it.”
(ii) This checkpoint advanced the State’s interest in curbing the drunk driving problem, noting that the
use of a permissible checkpoint is but one of many reasonable alternatives to remedying the problem,
and “the choice among such reasonable alternatives remains with the governmental officials who have
a unique understanding” of the problem and the resources available to combat it.
(iii) The intrusion, both objective and subjective, was slight, pointing out the brevity (25 seconds) of
the average encounter. The Court also noted that any subjective intrusion, such as making a motorist
fearful or annoyed, was diminished by the fact that motorists could plainly see all vehicles were being

See also U.S. v. Hawkins, 249 F.3d 867 (9th Cir. 2001), listing five factors courts should consider in
determining the reasonableness of a checkpoint or roadblock: (i) the checkpoint’s primary purpose; (ii)
whether all vehicles are stopped; (iii) whether officers exercise discretion over the checkpoint’s
operation; (iv) whether the checkpoint is well identified; and (v) whether stops made involve a minimal

However, in City of Indianapolis v. Edmond, 531 U.S. 32 (2000), the U.S. Supreme Court found that
roadblocks and checkpoints conducted for the “primary purpose” of “uncover[ing] evidence of
ordinary criminal wrongdoing” violate the Fourth Amendment. Roadblocks should be directed toward
administrative purposes, such as ensuring highway safety (for example, by removing the “immediate,
vehicle-bound threat” caused by drunk drivers) or, where appropriate, policing the Nation’s borders
(by checking for illegal immigrants in areas reasonably close to the border); they must not be motivated
by “the general interest in crime control.” Thus, so-called “
drug checkpoints,” staffed with drug-
sniffing dogs and conducted for the primary purpose of discovering and interdicting illegal narcotics,
were unconstitutional. The Court did note that if exigent circumstances were present, an appropriately
tailored roadblock whose primary purpose was crime-control would almost certainly be permitted (for
example, to thwart an imminent terrorist attack or to catch a dangerous criminal likely to flee by a
particular route). Of course, if police uncover evidence of criminal wrongdoing at a valid roadblock,
they may seize the evidence and arrest its possessor.

Legal Citations Provided by Lexis-Nexis

Santa Clarita DUI Attorney Matthew Ruff has over 25 years experience fighting DUI charges and
challenging Sobriety Checkpoints on Constitutional ground in California.  No case is too big or too
small to defend.  The consequences of a driving under the influence conviction is long lasting and
substantial.  You only get one chance to fight a DWI.  

If you have been arrested at a DUI or drivers license checkpoint Contact the local Santa Clarita
Valley Criminal Defense Team for  information and options available to you at   (661) 327-7833
DUI Attorney in Santa Clarita