An appellate court in Illinois has tossed out the 2014 conviction of a motorist who was sentenced to jail as the byproduct of an undocumented “anonymous tip.”

The supposed concerned citizen reported that the motorist was drunk. He was not, but it turned out he was driving on a suspended license, for which he was arrested. The appeals court ruled that the tip was too vague and unreliable to be the sole justification for a traffic stop.

Drunk driver tip was not even correct

A Chicago police officer claims he received an anonymous call about a “male Hispanic” who was driving drunk on a certain road. The caller described a black Ford Expedition and a partial license plate number. Based on the anonymous tip, the officer located and followed the suspect. Despite observing no traffic violations or erratic driving, he pulled the driver over.

During the traffic stop, the officer determined the man was not impaired. But his license came up as suspended, and he was arrested instead on that charge. He was ultimately given a 30-day jail sentence.

Appeals court was skeptical of vague, unverified tip

The Illinois Appellate Court, in Illinois v. Lopez, overturned the lower court’s conviction. The panel concluded that a traffic stop based on a flimsy and unverified tip was invalid. There is no record that the tipster called 911; he or she allegedly called the arresting officer.

The prosecution relied on a U.S. Supreme Court case, Navarette v. California, which likewise hinged on an anonymous tip. But the tipster in that case had provided a specific eye-witness account of dangerous behavior. In the Lopez case, the tipster provided no details or rationale for the claim of drunk driving. The appeals court also noted the driver did nothing suspicious once he was tailed to corroborate the tip and merit a traffic stop.

His conviction was overturned as a violation of his Fourth Amendment right to be free from unreasonable search and seizure. Criminal convictions can be appealed if the court erred in allowing (or not allowing) certain evidence, or otherwise unfairly prejudicing the outcome.