Last Monday, the Supreme Court ruled 5-3 that evidence found by police officers even after they stop someone illegally can still be used if the searches happen after the officers learn of an unrelated outstanding arrest warrant. In a particularly powerful dissent, Justice Sonia Sotomayor explained the dangers of the majority ruling, particularly for people of color.

In the case, Utah v. Strieff, a police officer investigating possible narcotics activity in a house decided to stop Edward Strieff, who left the house, even though there were no reasonable grounds for the stop, which made it illegal. The officer then ran a check on Mr. Strieff, found a warrant for a minor traffic violation, and arrested him on that prior offense. The officer then searched him, found illegal drugs, and charged him accordingly. Even though the Utah Supreme Court found that the evidence should have been suppressed because of the illegal stop, the Supreme Court reversed because of the prior unrelated warrant.

“The court today holds that the discovery of a warrant for an unpaid parking ticket will forgive a police officer’s violation of your Fourth Amendment rights,” Sotomayor wrote. “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.” As she continued, “if the officer discovers a warrant for a fine you forgot to pay, courts will now excuse his illegal stop and will admit into evidence anything he happens to find by searching you after arresting you on the warrant.” Justices Sotomayor and Kagan (who also dissented as did Justice Ginsburg) explained that this danger is far from hypothetical: federal and state databases show more than 7.8 million outstanding warrants, most of which are for minor traffic and other offenses. For example, in Ferguson, Missouri, which has a population of 21,000, there are 16,000 such outstanding warrants.

In a part of her dissent that she wrote only for herself, Sotomayor highlighted the problems that minorities face due to police stops. “For generations,” she explained, “black and brown parents have given their children ‘the talk’ – instructing them never to run down the street, always keep your hands where they can be seen, do not even think of talking back to a stranger – all out of fear of how an officer with a gun will react to them.” She added that people “routinely targeted by the police” are the “canaries in the coal mine whose deaths, civil and literal, warn us that no one can breathe in this atmosphere,” She continued that “unlawful police stops corrode all our civil liberties and threaten all our lives.” Until the voices of these people “matter, too,” she concluded, “our justice system will continue to be anything but.”

The majority tried to minimize the impact of its ruling, stating that the stop was not a “flagrant” violation or part of a “dragnet” or “systematic or recurrent police misconduct,” but simply an “isolated instance” of an error by a police officer. Time and future cases will tell if Strieff will truly be an isolated case and if the Court will prevent abuse. Much will depend on the future votes of Justice Breyer, who joined the majority in the case, and of course the unfilled vacancy on the Court being held open by Republican obstructionism. But Sotomayor’s strong opinion was a remarkable and important statement that will hopefully help shape the future direction of the Court. As University of Chicago law professor Justin Driver put it, her dissent is “the strongest indication we have yet that the Black Lives Matter movement has made a difference at the Supreme Court— at least with one justice.”