The exclusionary rule is threatened with extinction by the U.S. Supreme Court decision of Herring v. United States. Herring carved an exception out of the 1961 decision in Mapp v. Ohio, by sanctioning warrantless police searches arising out of negligence rather than willful misconduct. The Herring opinion holds that if police were simply negligent (in that case by failing to update a database in a neighboring jurisdiction), then the search of someone’s home is justified even without a valid search warrant.
The problem with the admissibility of evidence turning on the difference between negligent and willful police conduct is the lack of a bright line. The result will probably be many interpretive court opinions, and a great number of people losing their Constitutional protection from police bursting into their homes and rifling their belongings without legal justification.
If police negligence is absolved of its natural consequence, which is the exclusion from evidence of items obtained without a valid search warrant, then the procedural accuracy of law enforcement becomes a lower priority.
Consider this example: An under-budgeted precinct house might assign the updating of electronic records to fewer staff, because after the Herring decision there is no longer any punishment (disincentive) associated with updating records more slowly. Would it be negligence if an intentional paperwork backlog or series of layoffs meant that police had not yet gotten around to removing a stale warrant from their computer system? This is not exactly negligent, nor could it be called willful misconduct for authorities to take more time than if they had better equipment or more personnel. It is unclear from the reasoning in Herring if a warrantless search would be upheld in this circumstance or not.
Herring not only establishes an unclear legal standard, it also unacceptably jeopardizes the privacy rights of innocent people.