The season for DUI Checkpoints is approaching fast. Episode 036 (Duration 32:16).

Here we lay out the foundations in the law authorizing DUI checkpoints. Once, this roadmap is established common questions about DUI checkpoints can be answered.

DUI Checkpoint Legal Foundations

People v. Ray

People v. Ray, 327 Ill.App.3d 904, 764 N.E.2d 173 (5th Dist. 2002), citing City of Indianapolis v. Edmond, 531 U.S. 32, 121 S.Ct. 447 (2000).

The defendant in People v. Ray was stopped in a drug interdiction checkpoint.

The law enforcement purpose for the traffic stop was to specifically search for and detect illegal drugs. After police dogs “indicated” (positively sniffed) on Ray’s car, he was further detained. His car was searched. Drugs were discovered.

The court said that the police cannot use a traffic checkpoint for this type of generalized crime control.

Generalized crime control, in this context, was defined as situations that specifically target the drivers. The driver’s themselves were being investigated and scrutinized.

Yes, controlling drugs in society is an important state interest. However, the privacy interests of each individual driver was weighed more heavily. If this kind of traffic checkpoint were allowed, there would be no practical restraint on the police.

Police would be to create any number of traffic roadblocks for any reason. Giving police unfettered control over when and where they could set up roadblocks against individual liberty is itself unreasonable.

Illinois v. Lidster

Illinois v. Lidster, 540 U.S. 419, 124 S.Ct. 885 (2004).

This case reminds us that not every traffic checkpoint is illegal.

In this case, the United States Supreme Court held that a traffic checkpoint set up to gather information on a homicide was permissible. In this type of a situation, the balancing of the interests falls on the side of law enforcement. The state interest was in seeking information on a death after a hit-and-run that occurred the day before the checkpoint was set up.

Investigating a death is a compelling state interest. The individual privacy interest that was being impeded was weighed as being less significant. This side of the scale was affected by the fact that the drivers, themselves, were not the targets of a criminal investigation.  

The drivers were merely being asked to provide information. This was something they were likely glad to do. It is reasonable to infringe on individual privacy concerns when the police are conducting a separate high level investigation.

People v. Bartley

People v. Bartley, 109 Ill. 2d 273, 486 N.E.2d 880 (1985).

DUI checkpoints combine factors of both permissible and impermissible traffic roadblocks.

In a DUI checkpoint, the driver is the target. The driver is under investigation. The driver is the focus of police scrutiny. Courts have said this a huge factor for illegality.

On the other hand, the State declares their interest as nothing short of saving lives.