The U.S. Supreme Court's ruling in Thompson v. Clark on Monday makes it easier to sue police and prosecutors for malicious prosecution.

At the center of the ruling is a case of diaper rash, NPR reports.

Larry Thompson was living with his then fiancée (now wife) and their newborn baby when his sister-in-law, who apparently suffered from mental illness, called 911, claiming that Thompson was abusing the baby. When EMT officers arrived, they were admitted to the apartment by the sister-in-law, but Thompson, unaware of her 911 call, told them they must have the wrong address.

The EMT officers left, but returned to the apartment with four New York City police officers. This time Thompson answered the door and refused to admit them unless they had a search warrant. The police then threw Thompson on the floor and handcuffed him while the EMTs examined the baby. The only marks they found were diaper rash, but the baby was taken to the hospital where the diaper rash diagnosis was confirmed.

Thompson, however, was tossed into jail for two days and charged with resisting arrest and obstructing governmental administration. Prosecutors subsequently dropped all charges without any explanation.

Thompson sued, alleging malicious prosecution. But under the federal appeals court precedent in New York, Thompson had to prove that his innocence had been "affirmed." The dropping of charges without explanation was not enough.

On Monday, the Supreme Court sided 6-to-3 with Thompson in declaring that he did not have to show an "affirmative indication of innocence."

Justice Brett Kavanaugh wrote the majority opinion, declaring that a plaintiff need only show that his prosecution ended without a conviction, and Thompson did that here.