Despite the U.S. Supreme Court operating with one less justice, the Court has continued to issue surprising rulings on everything from immigration, to abortion, to blood tests of suspected drunk drivers. By a 5 to 3 vote, the Supreme Court ruled that evidence obtained after an illegal search may be admissible, effectively broadening the exclusionary rule.

In the case of Utah v. Strieff, a narcotics detective was conducting surveillance on a South Salt Lake City home, based on an anonymous tip about narcotics activity. Over the course of a week, Detective Douglas Fackrell observed a number of people making brief visits to the house, which made the officer suspicious. Officer Fackrell stopped Edward Strieff after he left the residence, asking what he'd been doing at the house.

Officer Fackrell asked for Strieff's identification, which he relayed to a police dispatcher. The dispatcher said Strieff had a warrant out for his arrest on a traffic violation. The officer then searched Strieff, finding methamphetamines and drug paraphernalia. Strieff was arrested.

Strieff sought to suppress the drug evidence, arguing that it was derived from an illegal investigatory stop. The trial court denied the motion, affirmed by the Utah Court of Appeals, then reversed by the Utah Supreme Court. The case was then taken up to the U.S. Supreme Court.

In the majority opinion, the Supreme Court found that even though there was a Fourth Amendment violation, exclusion of the evidence does not apply when the costs of exclusion outweigh the benefits. “We hold that the evidence the officer seized as part of the search incident to arrest is admissible because the officer's discovery of the arrest warrant attenuated the connection between the unlawful stop and the evidence seized incident to arrest,” wrote Justice Clarence Thomas.

The exclusionary rule generally allows for the suppression of evidence gathered in violation of the defendant's constitutional rights, including evidence gathered from an unlawful search or seizure. The exclusionary rule may also apply to subsequent evidence found after the initial unlawful search, known as “fruit of the poisonous tree.” There are narrow exceptions to the exclusionary rule; however, this recent ruling may be effectively broadening the attenuation exemption.

The decision was controversial, even within the Court. Justices Sotomayor and Kagan each wrote a dissenting opinion, joined in by Justice Ginsburg. “This case allows the police to stop you on the street, demand your identification, and check it for outstanding traffic warrants—even if you are doing nothing wrong,” wrote Sotomayor.

As Sotomayor pointed out, more than 7.8 million people in the U.S. have outstanding warrants, mostly for minor offenses. In Ferguson, Missouri, over 75% of residents are subject to arrest warrants. These warrants may allow police officers to stop people without cause, to check for outstanding warrants.

Sotomayor strongly disputed that this case was an isolated incident, with no indication that these types of unlawful stops are systemic or recurrent. “We must not pretend that the countless people who are routinely targeted by police are ‘isolated,'” Sotomayor wrote. “They are the canaries in the coal mine whose deaths, civil and literal, warn us that no one can breathe in this atmosphere. They are the ones who recognize that unlawful police stops corrode all our civil liberties and threaten all our lives. Until their voices matter too, our justice system will continue to be anything but.”