According to Mapp v. Ohio, which legal principle is applied to evidence seized illegally?

In the case of Mapp v. Ohio, the Supreme Court established a significant legal principle regarding the use of evidence obtained through unlawful searches and seizures. The Court ruled that evidence obtained in violation of the Fourth Amendment, which protects against unreasonable searches and seizures, is inadmissible in state courts. This ruling extended the exclusionary rule, which was previously applicable only to federal cases, to state courts as well, ensuring that illegally obtained evidence cannot be used in any criminal prosecution.

This principle reinforces the idea that law enforcement must adhere to constitutional standards when conducting searches and seizures, thereby protecting citizens' rights. The ruling aims to deter police misconduct, ensuring that the justice system does not benefit from illegal actions by law enforcement. Hence, the correct answer reflects this foundational legal standard that prohibits the use of illegally seized evidence in court.