The first point that would occur to an English-speaking person not conversant with the vagaries of our jurisprudence is that the Fourth Amendment says nothing of excluding evidence from a trial. It is excluded because of something called the Weeks rule as Justice Hugo L. Black, in dissent, explains:
 

It was not until 1914 . . . that the Court in Weeks v. United States, 232 U.S. 383, stated that the Fourth Amendment itself barred the admission of evidence seized in violation of the Fourth Amendment. The Weeks opinion made no express confession of a break with the past. But if it was merely a proper reading of the Fourth Amendment, it seems strange that it took this Court nearly 125 years to discover the true meaning of those words. The truth is that the source of the exclusionary rule simply cannot be found in the Fourth Amendment. That Amendment did not when adopted, and does not now, contain any constitutional rule barring the admission of illegally seized evidence.

Evidence that the murdered girl had been in an automobile belonging to Coolidge was discovered by a vacuum search of the vehicle by New Hampshire authorities. Coolidge’s contention was that this evidence was obtained in violation of the Fourth Amendment and should have been excluded under the Weeks rule. But the Fourth Amendment prohibits only unreasonable searches and seizures. Was there anything unreasonable about the seizure of the car and the vacuum search which followed?