In the case of Utah v. Strieff, the U.S. Supreme Court ruled in a 5-3 decision that evidence found during an unlawful police stop could be used in court if the person stopped had an outstanding arrest warrant. The case involved Edward Strieff, who was unlawfully detained by a detective conducting surveillance on a house in South Salt Lake City, Utah due to suspected drug activity. During this detention, it was discovered that Strieff had an outstanding "small traffic warrant". He was arrested and searched; methamphetamine and drug paraphernalia were found on his person. While lower courts agreed that the initial stop was illegal as there were no reasonable grounds for suspicion, they disagreed over whether or not the evidence obtained should be suppressed under what is known as 'the exclusionary rule'. This rule generally prohibits prosecutors from using illegally obtained evidence at trial but has some exceptions including one where such information would have inevitably been discovered by legal means - which applied here because of Mr.Strieff's existing warrant.

In the dissenting opinion for Utah v. Strieff, Justice Sonia Sotomayor argued that the majority's decision allows and validates unconstitutional police stops. She contended that this ruling could potentially increase racial profiling by law enforcement officers who can now stop, question, and search individuals without reasonable suspicion of criminal activity as long as they can find an outstanding warrant during their investigation. This would disproportionately affect communities with high numbers of outstanding warrants due to minor infractions such as traffic violations or unpaid fines. Furthermore, she expressed concern about how this decision undermines Fourth Amendment protections against unreasonable searches and seizures by rewarding police misconduct rather than deterring it.