Which of the following U.S. Supreme Court cases extended the exclusionary rule to the states?

The correct answer is the case of Mapp v. Ohio, which extended the exclusionary rule to the states through the incorporation doctrine. This landmark decision established that evidence obtained in violation of the Fourth Amendment, which protects against unreasonable searches and seizures, cannot be used in state courts. Prior to this ruling, the exclusionary rule was only applicable to federal cases, as established in Weeks v. U.S. However, Mapp v. Ohio applied that same principle to state courts, ensuring that all individuals, regardless of whether they were prosecuted under federal or state law, had the same protections against unlawful evidence gathering.

This decision was crucial for civil liberties because it solidified the expectation that law enforcement in all jurisdictions must adhere to constitutional protections, thereby reinforcing the principle that the rights guaranteed by the Constitution apply uniformly across the nation. The other cases mentioned do not relate to the establishment of the exclusionary rule at the state level, which is specific to Mapp v. Ohio.