[3] In the 1914 case Weeks v. United States, the U.S. Supreme Court prohibited the admissibility of evidence obtained through unreasonable searches or seizures in federal criminal prosecutions, thereby establishing the exclusionary rule.
In Mapp, the majority gave three rationales for enforcing the exclusionary rule under the Constitution: protecting a defendant's Fourth Amendment rights, promoting judicial integrity, and deterring improper searches and seizures.
[11] In Arizona v. Evans (1995),[12] the Court held that evidence gathered because of a clerical error (here, a search warrant that was not properly removed from the police database) was admissible under the good-faith exception.
The majority explained that the purpose of the exclusionary rule is to deter police misconduct, not punish mistakes made by court employees.
The majority held that it did when the police mistake was due to a simple, isolated incident of negligence rather than systemic error or a deliberate or reckless disregard of constitutional requirements.
[22] Herring v. United States, which held that negligent actions by the police in some circumstances may still fall under the good-faith exception, has also invited scrutiny.