Michigan v. DeFillippo

Background

Detroit police stopped a man late at night after a report about two possibly intoxicated people. The man gave inconsistent answers about his identity, was arrested under a recently amended Detroit stop-and-identify ordinance, and was searched; officers found drugs. A state appeals court held the ordinance unconstitutionally vague, suppressed the drug evidence, and the State appealed to the Supreme Court.

Reasoning

The Court asked whether an arrest made in good-faith reliance on a presumptively valid local ordinance remains valid even if the ordinance is later held unconstitutional. The majority said yes. It found the officer had probable cause based on the man's behavior and evasive answers, and that the search was lawful as incident to a valid arrest. The Court emphasized that officers are expected to enforce laws until courts declare them unconstitutional, except when a law is obviously and flagrantly invalid.

Real world impact

The ruling makes it more likely that evidence found after arrests under local stop-and-identify laws will be admissible if officers acted reasonably and in good faith. Police may rely on such ordinances during stops, but the Court noted limits: blatant unconstitutional laws or patterns of pretextual arrests could still be challenged. The case was reversed and remanded for further proceedings consistent with the opinion.

Dissents or concurrances

Justice Brennan's dissent warned the ordinance and the arrest violated Fourth Amendment protections, arguing people may not be compelled to identify themselves and that the decision risks allowing circumvention of constitutional limits; Justice Blackmun concurred but noted similar concerns.