The US Supreme Court on Friday ruled that evidence from an objectively unconstitutional automobile search can still be admissible in court as long as the search took place prior to court decisions that recognized stronger protections in the Fourth Amendment. Specifically, the April 2009 decision in the case Arizona v. Gant overturned prior precedent and required police to get a warrant to search a car when an arrested suspect posed no realistic threat to officer safety (view ruling). Willie Davis was arrested over two years earlier in Greenville, Alabama when that rule did not apply.

Davis had been riding in a car driven by Stella Owens who was pulled over from drunk driving. During the stop, Davis and Owens were put in the backs of separate patrol cars and searched. Davis, a felon, had a revolver inside the pocket of his jacket. Davis challenged the seizure, and as his appeal was being heard, the Gant decision came down. Nevertheless, the Eleventh US Circuit Court of Appeals found that the search of Davis was indeed unconstitutional, but the evidence should be admitted. The supreme court majority led by Justice Samuel Alito agreed that the exclusionary rule should not apply.

"Exclusion is not a personal constitutional right, nor is it designed to redress the injury occasioned by an unconstitutional search," Alito wrote for the majority. "The rule's sole purpose, we have repeatedly held, is to deter future Fourth Amendment violations."

The majority reasoned that police officers following the binding precedent set by appellate courts could not be deterred from conduct that at the time was neither illegal nor reckless.

"The search incident to Davis's arrest in this case followed the Eleventh Circuit's Gonzalez precedent to the letter. Although the search turned out to be unconstitutional under Gant, all agree that the officers' conduct was in strict compliance with then-binding circuit law and was not culpable in any way," Alito explained. "Under our exclusionary-rule precedents, this acknowledged absence of police culpability dooms Davis's claim.... It is one thing for the criminal to go free because the constable has blundered. It is quite another to set the criminal free because the constable has scrupulously adhered to governing law."

Justices Stephen Breyer and Ruth Bader Ginsburg filed a dissent arguing the majority decision ultimately erodes the protections of the Fourth Amendment by creating yet another "good faith" exception to the constitutional right. This, Breyer and Ginsburg argued, would accelerate the number of illegal searches as lower courts followed the high court's lead and allowed more illegally seized evidence to be admitted.

A copy of the decision is available in a 240k PDF file at the source link below.