Legal Requirements for Sobriety Checkpoints

When conducting sobriety checkpoints, police must follow strict guidelines outlined by the California Supreme Court in the landmark case Ingersoll vs. Palmer. If police do not follow the criteria laid out in Ingersoll, the DUI / DWI roadblock isn't lawful, and any evidence gathered during a drunk driving arrest may not be admissible in court. The skilled DUI / DWI defense lawyers from The Kavinoky Law Firm can determine whether a sobriety checkpoint was conducted lawfully.

In the Ingersoll decision, the Court outlined eight (8) requirements designed to minimize the intrusiveness on the individual and balance the needs of society to keep drunk drivers off the road.

According to Ingersoll, supervisory police officers, not officers in the field, must make decisions about the establishment and location of sobriety checkpoints. This is important to reduce the potential for arbitrary and random enforcement.

The Court's decision also limited the discretion of police to stop drivers at checkpoints. Police should use a neutral mathematical formula, such as every third, fifth, or tenth driver, to determine which vehicles to stop. This requirement takes away the discretion of the individual officer to choose to stop drivers based on appearance.

Maintaining safety for motorists and officers must be a primary consideration. Proper lighting, warning signs and signals, and clearly identifiable official vehicles and personnel are required. The checkpoint should only be operated when the traffic volume allows the operation to be conducted safely.

A supervisory officer must choose a location that will be most effective in actually stopping drunk drivers, such as roads which have a high incidence of alcohol-related accidents and arrests.

The time and duration of DUI / DWI roadblocks also must be considered. Police must use good judgment in scheduling sobriety checkpoints, with an eye to effectiveness of the operation, and with the safety of motorists in mind. So long as these considerations are in effect, there are no specific rules about the timing or duration of the roadblock.

Sobriety checkpoints also must be highly visible so that drivers can easily see the nature of the roadblock. Flashing warning lights, adequate lighting, police vehicles, and the presence of uniformed officers all contribute to visibility. Not only are such factors important for safety reasons, but advance warning will reassure motorists that the stop is duly authorized.

Each driver should be stopped only long enough for the officer to question the driver briefly and to look for signs of intoxication, such as slurred speech, alcohol on the breath, and glassy or bloodshot eyes. If the driver doesn't show any signs of impairment, he or she should be permitted to drive on without further delay. If the officer does observe signs of impairment, the driver may be directed to a separate area for a field sobriety test. At that point, probable cause must propel any additional investigation, and general principles of detention and arrest would apply.

The public should be informed in advance about sobriety checkpoints, although police are not required to disclose its specific location. Publicity both reduces the intrusiveness of the stop and increases the deterrent effect of the roadblock. Advance notice is intended to limit the intrusion upon the individual's personal dignity and security because those stopped would anticipate and understand what was happening. Further, advance publicity serves to establish the legitimacy of roadblocks in the minds of motorists.

Drivers who take steps to avoid a roadblock cannot be stopped merely because they attempted to avoid the checkpoint. However, if the driver commits a vehicle code violation or displays obvious signs of intoxication, there is adequate probable cause to pull over the motorist, after which point general principles of detention and arrest apply.

The California Supreme Court's Ingersoll decision gave police latitude in conducting sobriety checkpoints, but it also established guidelines under which the roadblocks must be operated. If police don't follow that protocol, the evidence gathered as a result of the roadblock may be suppressed as a violation of the driver's Fourth Amendment rights. A California DUI / DWI lawyer who is well-versed in the requirements of sobriety checkpoints can determine whether a roadblock was lawfully executed, and whether any evidence gathered is likely to be suppressed.