Legal Requirements for California DUI Sobriety Checkpoints

It has been ruled by the Supreme Court that the primary purpose of sobriety check points is not to discover evidence of an offense or to even make drunk driving arrests, but rather to promote public safety by stopping intoxicated individuals from endangering the public and driving.  What this means is that a California DUI sobriety checkpoint serves as a regulatory purpose and one that does not require warrants because it is not a criminal investigation. 

California Drunk Driving law and the courts have outlined strict procedures that must be followed when it comes to sobriety checkpoints.  The police must provide advance notice to the public of the sobriety checkpoint; however, they are not required to provide notice of the exact location.  This advance notice serves to establish legitimacy for the roadblock and helps to reduce the intrusiveness of the stop.  The decision behind providing notice is to limit intrusion upon one’s personal dignity and security by allowing those who are stopped to anticipate a stop.

The Ingersoll vs. Palmer Ruling

In the landmark Supreme Court case Ingersoll vs. Palmer, certain protocol must be followed if the checkpoint is to be considered lawful.  Otherwise, any evidence gathered during a driving under the influence arrest may not be admissible in court.  According to the Ingersoll ruling, supervisory police officers, not officers in the field, must be the officers who set up sobriety checkpoints. This is an important requirement whereby the potential for arbitrary and random police enforcement is reduced. 

Additionally, the Ingersoll ruling also places limitations on the police as to how and when drivers should be stopped.  They must utilize a neutral mathematical formulation, such as stopping every driver, or every second, fourth, or tenth driver.  This way it is not left up to the discretion of the police officer to select which drivers they should stop without having any legitimate cause.  In setting up sobriety checkpoints, the police must also consider the safety of both motorists and police officers.  In order to minimize risk, warning signs and signals, and proper lighting need to be placed at the scene as well as clearly identifiable police vehicles.  Also, the actual placing of roadblocks is regulated and the location must be one where a high incidence of alcohol-related accidents and arrests has already occurred.

It was also stated in the Ingersoll decision that drivers who seek to avoid a sobriety checkpoint may not be “stopped and detained” simply because they attempted to do so.  However, if a driver commits a traffic violation or exhibits obvious signs of intoxication, the police do have adequate cause to stop the motorist.  In such instances, an experienced California DUI lawyer can sometimes successfully argue that such obvious signs did not exist and therefore the stop was unlawful and get any evidence gathered thereafter suppressed.   Although the Ingersoll decision helped to legitimize California DUI sobriety checkpoints, it also established strict procedures that must be followed by the police.  If the police fail to follow the factors outlined by the Supreme Court, any evidence obtained as a result of the sobriety checkpoint may be suppressed.  A knowledgeable California DUI/DWI attorney can determine whether or not a sobriety checkpoint was conducted lawfully and if not, most often obtain a “not-guilty” verdict for clients who are suspected of drunk driving.