Which case established the exclusionary rule for federal courts?

• A. Mapp v Ohio
• B. Weeks v United States
• C. Miranda v Arizona
• D. Terry v Ohio

Answer: (B)

The main idea here is the exclusionary rule, which says evidence obtained in violation of the Fourth Amendment cannot be used in court. Weeks v United States is the case that first established this rule for federal prosecutions. In Weeks, evidence seized by federal officers without a proper warrant was deemed inadmissible in federal court, creating the remedy of suppression to deter unlawful searches.

Later cases expanded or clarified the rule in other ways—Mapp v United States extended it to state courts, applying it to state prosecutions through incorporation; Miranda v Arizona handles interrogation rights, not the admissibility of evidence from searches; Terry v Ohio deals with stop-and-frisk standards. But for the question about establishing the rule for federal courts, Weeks v United States is the correct reference.