## Facts

- Two Michigan deputies observed David Long driving erratically at excessive speed at night; the car swerved into a ditch.
- Long, the sole occupant, appeared intoxicated or impaired and did not respond to requests for license and registration.
- As Long walked toward an open car door to retrieve documents, officers followed and saw a hunting knife on the driver’s-side floorboard.
- Officers stopped Long and conducted a pat-down that found no weapons.
- An officer illuminated the car’s interior, saw an object protruding under the front-seat armrest, lifted the armrest, and found an open pouch containing what appeared to be marijuana.
- Long was arrested for marijuana possession; additional marijuana was later found in the car and trunk.

## Issues

1. Whether the Supreme Court had jurisdiction to review the state judgment when the state court referenced the state constitution but did not clearly state that state law independently controlled the result.
2. Whether the Fourth Amendment permits a protective search of a vehicle’s passenger compartment during a lawful investigatory stop when officers reasonably suspect the suspect is dangerous and may gain immediate control of a weapon.

## Decision

- The Supreme Court held it had jurisdiction because the state decision appeared to rest primarily on federal law and did not clearly rest on an adequate and independent state ground.
- The Court held the protective search of the passenger compartment was reasonable under *Terry* principles.
- The Court reversed the state supreme court and reinstated the conviction.

## Legal Principles

- When a state-court decision fairly appears to rest primarily on federal law or to be interwoven with federal law, and the opinion does not clearly state an adequate and independent state ground, the Supreme Court will presume the state court relied on federal law and may review the judgment.
- In determining whether an adequate and independent state ground clearly supports the judgment, the Supreme Court will generally look to the face of the state-court opinion rather than materials outside it.
- During a lawful investigatory stop, officers may conduct a limited protective search of a vehicle’s passenger compartment if specific, articulable facts support reasonable suspicion that the suspect is dangerous and may gain immediate control of weapons.
- The protective search may extend to areas of the passenger compartment (including containers) where a weapon could be placed or hidden, so long as the search remains directed to officer safety.

## Conclusion

The Court established a presumption favoring federal review when a state court’s reasoning is interwoven with federal law but does not clearly rest on an independent state ground, and it extended *Terry* to permit limited protective searches of a vehicle’s passenger compartment when officers reasonably suspect a detained person is dangerous and could access a weapon.


Michigan v. Long, 463 U.S. 1032 (1983)