## Facts

- Police investigated a fatal hit-and-run in Lombard, Illinois, in which a bicyclist was killed.
- About one week later, officers set up a highway checkpoint at the same location and around the same time of night as the crash.
- Officers stopped each vehicle for about 10–15 seconds, asked whether occupants saw anything the prior weekend, and handed out a flyer requesting information.
- Robert S. Lidster approached the checkpoint, swerved, and nearly struck an officer.
- An officer smelled alcohol on Lidster’s breath; Lidster failed a sobriety test and was arrested for driving under the influence.
- Lidster was convicted in Illinois state court based on evidence obtained after the checkpoint stop.

## Issues

1. Whether a checkpoint that briefly stops motorists to request information about a prior hit-and-run is an unreasonable seizure under the Fourth Amendment.
2. Whether such an information-seeking checkpoint is barred by the rule against suspicionless “general crime control” checkpoints.

## Decision

- The Supreme Court reversed the Illinois Supreme Court and remanded.
- The Court held the checkpoint stop was a Fourth Amendment seizure but was constitutionally reasonable.
- The Court distinguished checkpoints aimed at discovering crimes by the stopped motorists from checkpoints aimed at obtaining public assistance in investigating a crime committed by others.
- Applying a reasonableness balance, the Court found: (1) the public concern was grave (a death), (2) the checkpoint was suitably targeted to obtain useful information, and (3) the interference with liberty was minimal given the brief, uniform stops.

## Legal Principles

- Reasonableness under the Fourth Amendment requires balancing the public interest against the individual’s interest in freedom from arbitrary law-enforcement interference.
- A suspicionless checkpoint is not automatically unconstitutional when its primary purpose is to seek information from the public about a specific past crime, rather than to detect ordinary criminal wrongdoing by the stopped drivers.
- In information-seeking stops, individualized suspicion has limited relevance because the stop is not premised on suspicion of the stopped motorist.
- Courts assess checkpoint validity by examining the gravity of the public concern, the degree to which the checkpoint advances that concern, and the severity of the interference with personal liberty.

## Conclusion

The Court upheld a brief, targeted checkpoint designed to solicit information about a fatal hit-and-run, holding that such information-seeking stops may be reasonable under the Fourth Amendment even without individualized suspicion, and are distinct from prohibited “general crime control” checkpoints.


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