Weeks v. United States
Citation and Court
232 U.S. 383 (1914) — Supreme Court of the United States
Facts
Federal marshals entered Weeks’s home without a warrant and seized papers and documents used as evidence to convict him of using the mail to transport lottery tickets. Weeks moved to have the seized materials returned before trial, but the trial court denied the motion and admitted the evidence.
Issue
Does the Fourth Amendment prohibit the use in a federal criminal prosecution of evidence obtained through a warrantless search and seizure?
Holding
Yes; evidence obtained by federal officers in violation of the Fourth Amendment must be excluded from federal prosecutions.
Rule / Doctrine
The exclusionary rule: evidence obtained by federal law enforcement in violation of the Fourth Amendment is inadmissible in federal court. The government cannot use its own constitutional violations to secure a conviction.
Significance
Weeks established the federal exclusionary rule, the first major judicial remedy for Fourth Amendment violations. It laid the groundwork for the rule’s later extension to the states in Mapp v. Ohio (1961). The case is the foundational authority for the proposition that courts must not sanction unconstitutional police conduct by admitting the fruits of illegal searches.