On June 20, the Supreme Court voted 5 to 3 in a case involving evidence seized after an illegal police stop. Here's what Justice Sonia Sotomayor wrote in her blistering dissent. (Monica Akhtar/The Washington Post)

The Supreme Court ruled Monday that courts need not throw out evidence of a crime even if the arresting police officer used unlawful tactics to obtain it.

But the low-profile case more likely will be remembered for a fierce and personal dissent from Justice Sonia Sotomayor, who said the decision would exacerbate illegal stops of minorities. Her 12-page opinion explained “the talk” that black and brown parents have with their children about police interactions, invoked Ferguson, Mo., and, without direct acknowledgment, referenced the sentiments of the Black Lives Matter movement.

The court voted 5 to 3 to reverse a decision of the Utah Supreme Court that threw out drug-possession evidence seized from Edward Strieff in 2006.

Monday’s U.S. Supreme Court majority agreed that South Salt Lake police officer Douglas Fackrell did not have reasonable suspicion to stop Strieff as he exited a house being watched for drug activity. But once Fackrell radioed in and found that there was an outstanding warrant on Strieff for a traffic violation, he was able to arrest and search him, and the discovery of the drugs was legitimate, the justices ruled.

“While Officer Fackrell’s decision to initiate the stop was mistaken, his conduct thereafter was lawful,” Justice Clarence Thomas wrote for the majority. He said the intervening discovery of the warrant meant the search that discovered the drugs was allowed.

The ruling was unusual in one way because it was the first time since the death of Justice Antonin Scalia that one of the court’s consistent liberals — Justice Stephen G. Breyer — joined colleagues on the right to create a conservative majority.

But more memorable will be the blistering dissents written by Breyer’s fellow liberal justices Sotomayor and Elena Kagan, joined at least in part by Justice Ruth Bader Ginsburg.

Kagan’s was a point-by-point disagreement with “the majority’s misapplication” of the court’s precedents, a ruling she said offers police “incentive to violate the Constitution.”

But Sotomayor — “writing only for myself, and drawing on my professional experiences” — produced the kind of personal essay that has made the court’s only Hispanic member a hero to liberals and caused conservatives to label her an activist.

“The white defendant in this case shows that anyone’s dignity can be violated in this manner,” Sotomayor wrote. “But it is no secret that people of color are disproportionate victims of this scrutiny.”

She referenced writers Michelle Alexander, W.E.B Du Bois and Ta-Nehisi Coates, and wrote of the conversations that minority parents “for generations” have had with their children, “out of fear of how an officer with a gun will react to them.”

“By legitimizing the conduct that produces this double consciousness, this case tells everyone, white and black, guilty and innocent, that an officer can verify your legal status at any time,” Sotomayor wrote. “It says that your body is subject to invasion while courts excuse the violation of your rights. It implies that you are not a citizen of a democracy but the subject of a carceral state, just waiting to be cataloged.”

The strong language came in a case that had gotten little attention. It involved the Fourth Amendment’s protection against unlawful searches and seizures and a court-developed standard called the exclusionary rule, which excludes evidence obtained by police in an unlawful manner.

The Utah Supreme Court found that the rule applied to the situation involving Fackrell and Strieff.

Fackrell in December 2006 was checking out an anonymous tip that a house was being used for drug sales. He watched the house for about three hours over the course of a week.

At some point, Fackrell decided he would question the next person he saw leave the house, which was Strieff. Fackrell explained his purposes and asked Strieff for identification. He called in the information and found that there was a warrant for Strieff’s arrest on a minor traffic violation. He arrested Strieff, searched him and discovered drugs.

The Utah court said the evidence must be suppressed, because Strieff had no reason in the first place to suspect that Strieff had done anything wrong. It said the only way the search could be legal was if, after the initial stop, Strieff admitted to a crime or consented to the search.

But Thomas and the majority disagreed Monday.

The “discovery of the arrest warrant attenuated the connection between the unlawful stop and the evidence seized from Strieff incident to arrest,” Thomas wrote.

Fackrell’s initial instinct was unlawful, Thomas wrote, but there was no reason to believe that it was “part of any systemic or recurrent police misconduct. To the contrary, all the evidence suggests that the stop was an isolated instance of negligence that occurred in connection with a bona fide investigation of a suspected drug house.”

Thomas said that “were evidence of a dragnet search presented here,” the outcome might be different.

Besides Breyer, Thomas was joined by Chief Justice John G. Roberts Jr. and Justices Anthony M. Kennedy and Samuel A. Alito Jr.

Sotomayor replied that “the Fourth Amendment does not tolerate an officer’s unreasonable searches and seizures just because he did not know any better.”

She added: “Respectfully, nothing about this case is isolated.”

She and Kagan both noted that outstanding warrants are now a common feature in American life. A Justice Department report in the aftermath of the riots in Ferguson found that there were 16,000 outstanding warrants in the city of 21,000 residents.

“The states and federal government maintain databases with over 7.8 million outstanding warrants, the vast majority of which appear to be for minor offenses,” Sotomayor wrote. “We must not pretend that the countless people who are routinely targeted by police are ‘isolated.’ They are the canaries in the coal mine whose deaths, civil and literal, warn us that no one can breathe in this atmosphere.”

The case is Utah v. Strieff.