Concept
Destruction of Evidence
Exigent circumstances, hot pursuit, and emergency aid
Destruction of Evidence
The third recognized exigency turns from protecting people to protecting proof. Entering a home without a warrant is presumptively unreasonable, but the presumption gives way when the exigencies of the situation make the needs of law enforcement so compelling that a warrantless entry is objectively reasonable, and the need to prevent the imminent destruction of evidence has long been counted among those exigencies.1 The modern statement of the rule comes from Kentucky v. King: police may enter a home without a warrant when they reasonably believe evidence is being destroyed, provided they did not create the exigency through an actual or threatened Fourth Amendment violation.2 This section sets out that baseline rule and the facts of King, then takes up the limit the Court placed on the rule and the additional limits it refused to add.
The reason for the exception follows from what a warrant is for. A warrant lets a neutral magistrate approve an entry before it happens, and the delay that involves is tolerable only when the evidence will still be there afterward. Drugs are the clearest case where it will not be, because they can be flushed down a toilet or rinsed down a drain in moments, and a person holding valuable drugs is unlikely to destroy them unless the person fears discovery by the police.3 If officers had to leave and return with a signed warrant, the object of the search might be gone before the paper arrived. The same fact explains why the exception needs a firm factual trigger. Almost every drug investigation could be described as one in which evidence might eventually be destroyed, so a bare possibility would swallow the warrant requirement in the cases where it is invoked most often. The exigency therefore rests on a reasonable belief about what is happening inside the home, formed from what the officers perceive, and a guess about what the occupants might do later does not supply it.
The facts of King show the rule at work. Lexington, Kentucky, officers followed a suspected drug dealer to an apartment complex after a controlled purchase of crack cocaine, and outside one apartment door they smelled burnt marijuana.4 They banged loudly on the door and announced that they were police, and as soon as they began knocking they heard noises from inside that they took to be consistent with the destruction of evidence.5 The officers then announced that they were going to enter, kicked in the door, and found King and others inside, and during a protective sweep they saw drugs in plain view.6 The trial court denied the motion to suppress, and the Kentucky Court of Appeals affirmed. The Kentucky Supreme Court reversed. It assumed that an exigency existed but held the exigent circumstances rule inapplicable, because the police should have foreseen that their conduct would prompt the occupants to try to destroy evidence.7
That ruling framed the question for the Supreme Court. Because the state court had assumed an exigency, the remaining issue was whether police conduct that provokes the destruction forfeits the exception. The Court held that it does not, so long as the police did not create the exigency by engaging or threatening to engage in conduct that violates the Fourth Amendment, and in that situation a warrantless entry to prevent the destruction of evidence is reasonable and allowed.8
Two earlier cases show how the pieces fit. In Santana the suspect knew officers were at her door, which made destruction of evidence a realistic expectation, and the same awareness is what the King officers could infer from noises that began the moment they knocked. Welsh supplies the counterweight: the minor offense there weighed against treating the entry as urgent, and the seriousness of the offense under investigation remains part of the reasonableness inquiry. Drug trafficking, the offense under investigation in King, is a grave offense of a different order.
This case-by-case exigency should be kept apart from the automobile exception. For a movable vehicle, exigent circumstances are presumed once probable cause exists, so officers need not show that evidence is actually being destroyed.9 A home receives no such presumption, which is why the home-entry cases demand specific facts pointing to destruction.
Police-Created Exigency
Lower courts had developed a police-created exigency doctrine, under which police may not rely on the need to prevent destruction of evidence when their own conduct created or manufactured that need.11 The doctrine could not rest on causation alone. In some sense the police always create the exigency, because people engaged in illegal conduct, drug offenders especially, destroy evidence mostly out of fear that it will fall into police hands.12 A rule that barred the exception whenever police conduct produced the destruction would therefore shrink the exception nearly out of existence.13 Courts accordingly demanded something more than causation, and they never agreed on what the something more should be.14
King answered with a test drawn from the reason warrantless searches are allowed at all. They are permitted when the circumstances make it reasonable to dispense with a warrant, so an exigency can be used when the police conduct that came before it was reasonable in the same sense.15 The exigent circumstances rule therefore applies when the police did not create the exigency by engaging or threatening to engage in conduct that violates the Fourth Amendment.16 The Court pointed out that other doctrines work the same way: officers may seize evidence in plain view if they did not violate the Fourth Amendment in reaching the spot from which they saw it, as in Horton v. California, and they may seek a consensual encounter if they are lawfully present where it occurs, as in INS v. Delgado.17 In each, the lawfulness of the officers' route to the place decides whether they may use what they find there. For the King officers, knocking and announcing their presence violated nothing, so the noises that followed were an exigency the police had not created through any violation, even though the knock set the sequence in motion.18
The test has two parts that do different work. The exigency requirement poses a question of fact about the scene: do the officers' perceptions support a reasonable belief that destruction is happening? The creation requirement poses a question about the officers' earlier conduct: was it, or did it threaten, a Fourth Amendment violation? Both must be satisfied, and since the state court in King had assumed an exigency, only the second was before the Court, so the decision does not relax the first. Limiting the doctrine to violations also answers the incentive problem behind it. Officers cannot profit from an exigency they bring about by unlawful means, because an illegal entry or an illegal threat to enter forfeits the exception, while lawful investigative steps that merely prompt a reaction do not.
Students lose this issue when they treat police conduct that merely triggers the destruction as manufacturing the exigency. Causation is present in nearly every case, so the limit applies only when the conduct was, or threatened, a Fourth Amendment violation.20
Rejected Add-On Tests
The bad-faith test fails for the reason the emergency-aid cases already gave. Fourth Amendment reasonableness is judged objectively, by asking whether the circumstances, viewed objectively, justify the action, and outside limited settings such as inventory searches and administrative inspections the Court has never held that an officer's motive invalidates objectively justifiable behavior.23 The desire to make arrests was irrelevant in Brigham City, and the desire to provoke or avoid anything is equally irrelevant here. A motive inquiry would also make a court reconstruct what the officers privately intended, which adds nothing to the question whether the entry was justified by what they perceived.
The foreseeability test fails because of how the exception works. People destroy drugs because they fear the police, so any police approach to a door makes some destruction foreseeable, and a foreseeability test would bring back the near-universal causation that the lower courts had already seen could not be the standard.24 Denying the exception whenever destruction is foreseeable would confine it to cases in which the occupants surprised the officers, which is almost none.
The missed-opportunity and poor-practice tests share a different defect. The third punishes officers for choosing one lawful step, a knock at the door, over another lawful step, applying for a warrant. Once the question is whether the officers' conduct violated the Fourth Amendment, the existence of a different, lawful course cannot matter, because the Amendment does not forbid a course merely because another was available. The test would also force a court, long after the fact, to decide at what moment the officers' information became sufficient to apply, a line that reasonable judges could draw differently and that the officers could not have known in advance. The fourth test imports departmental practice into constitutional law. Practices differ among agencies and change over time, and a departure from a manual may reflect only a different judgment about tactics, so a rule built on it would invite judges to second-guess investigative choices with the benefit of hindsight.
Rejecting the add-ons leaves a rule that officers can apply as events unfold: lawful conduct before the exigency, and a reasonable belief during it that evidence is being destroyed. Occupants keep real protection under that rule, since the entry still needs facts showing destruction and any violation or threat of violation forfeits the exception.
Police-Created Exigency
The destruction-of-evidence exigency invites an obvious objection: if officers may enter a home without a warrant whenever they hear evidence being destroyed, they might provoke the very sounds that justify the entry. Lower courts answered that worry with the police-created exigency doctrine, under which police may not rely on the need to prevent destruction of evidence when their own conduct created or manufactured that need.26 The doctrine could not simply bar the exception whenever police conduct caused the destruction. People who destroy drugs nearly always do so out of fear that the police are about to find them, so in some sense the police always create the exigency.27 A causation rule would therefore swallow the exception it was meant to police, and courts demanded something more than causation without ever agreeing on what that something was.28
Kentucky v. King ended the disagreement by returning to the reason warrantless entries are allowed at all.29 The Fourth Amendment permits a warrantless entry when the circumstances make it reasonable to dispense with the warrant, so an exigency remains usable when the police conduct that came before it was reasonable in the same sense.30 The exigent circumstances rule therefore applies when the police did not create the exigency by engaging or threatening to engage in conduct that violates the Fourth Amendment.31 The test is a lawfulness test. It does not ask whether police activity set events in motion, because that is almost always true. It asks whether that activity was itself a violation or the threat of one. The incentive logic follows from that structure: officers who stay within their rights are not punished for how people react, while officers who break or threaten to break the Amendment cannot profit from an emergency their own illegality provoked.
The facts of King show a lawful approach. After a controlled drug buy, Lexington officers followed the suspect toward an apartment complex, smelled marijuana outside one apartment door, knocked loudly, and announced that they were police.32 As soon as they began knocking they heard noises that they took to be consistent with the destruction of evidence, and only then did they announce that they were going to enter and kick in the door.33 Two features of that sequence carry the result. Officers without a warrant who knock on a door do no more than a private citizen could do, and the occupant has no obligation to open the door or to speak, so the knock compelled nothing.34 And the statement that the officers would enter came after the noises had begun, so it could not have produced them. What produced the noises was the occupants' choice to react to a lawful knock by moving evidence rather than by staying quiet and leaving the door closed.
The contrast case is a demand backed by a threat, and the single fact that separates it from King is the unlawful character of what the officers did before the destruction began.
The holding also leaves one requirement untouched. The Kentucky Supreme Court had assumed that an exigency existed and ruled against the state only because it thought the police should have foreseen the occupants' reaction.35 The United States Supreme Court decided only the creation question, so officers still need facts that support a reasonable belief that evidence is being destroyed or is about to be, and lawful conduct before the exigency does not supply that belief by itself.
The contrary view deserves a fair statement. The dissent, written by Justice Ginsburg, argued that the officers had probable cause and enough time to obtain a warrant before approaching the door, so the urgency they invoked was of their own making, and that allowing entry on these facts lets police avoid the warrant process whenever a knock draws a noise.36 The majority's answer is that the Amendment asks whether the officers' conduct was lawful, not whether they could have applied for a warrant sooner, a point taken up in the next section on the add-on tests the Court rejected.37 The worry was not new. In Santana, officers arrested McCafferty, the intermediary in a heroin sale, and then drove back to the house where she said the money was, and the dissent there objected that arresting the intermediary had itself generated the urgency to enter.38
The usual error is to ask whether the police caused the destruction, when the question the Court framed is whether the police acted or threatened to act unlawfully. A lawful knock that prompts a flush is an exigency the police did not create, and an unlawful demand that prompts the same flush is one they did.39
Rejected Add-On Tests
The bad-faith requirement is the intent inquiry, and it fails because Fourth Amendment reasonableness is measured by the circumstances rather than by the officer's private purpose. In Brigham City v. Stuart the Court declined to ask whether officers who entered a home to stop a brawl cared more about making arrests than about quelling violence, because an action is reasonable whenever the circumstances, viewed objectively, justify it, whatever the individual officer's state of mind.42 King carried that principle into the exigency setting, observing that outside limited contexts such as inventory searches and administrative inspections the Court has never held that an officer's motive invalidates objectively justifiable behavior.43 The principle protects occupants as well as officers. Terry v. Ohio warned that if an officer's subjective good faith alone could justify an intrusion, "the protections of the Fourth Amendment would evaporate."44 A rule that let good motives validate an entry and bad motives condemn one would keep the same private state of mind at the center of the analysis and merely turn it the other way, and a court could only guess at what the officers privately intended.
The other three requirements are hindsight inquiries, and they fail for a related reason: each would penalize officers for lawful choices. Foreseeability collides with the way the exception works. People destroy drugs because they fear the police, so any approach to a door makes some destruction foreseeable, and a foreseeability test would revive the near-universal causation that lower courts had already recognized could not be the standard.45 The missed-opportunity requirement faults the officers for knocking instead of applying for a warrant, yet both are lawful steps, and the Amendment does not forbid one lawful course merely because another was available. It would also make a judge decide, long after the event, the moment at which the officers' information became sufficient to support an application, a line that reasonable judges could draw differently and that officers cannot see while events unfold. The poor-practice requirement borrows departmental custom as a constitutional yardstick, although practices differ among agencies and a departure from a manual may reflect nothing more than a different judgment about tactics.
The majority's rule did not go uncontested. Justice Ginsburg's dissent argued that officers who have probable cause and time to seek a warrant should not be able to treat a noise behind a door as an emergency, because that lets police sidestep the magistrate whenever a knock draws a reaction.46 The majority's answer is that the Amendment constrains what officers do, so a lost chance to seek a warrant matters only if the officers' conduct itself violated or threatened to violate the Amendment.47 Occupants keep real protection under that answer, because the entry still requires facts supporting a reasonable belief that evidence is being destroyed, and unlawful or threatened unlawful conduct forfeits the exception.
The rule's central application is a knock by officers who already held probable cause and could have applied for a warrant. When the occupants react and the officers hear destruction, Kentucky v. King leaves the exigency intact, whatever the officers' earlier inaction and however foreseeable the reaction.48 One changed fact reverses that result.
Motive, foresight, and lost time moved the answer in neither direction here; the only fact that mattered was whether the officers' conduct violated or threatened the Amendment. Students lose this issue when they treat a missed chance to get a warrant as if it were unlawful conduct, because an unused chance to seek a warrant is not a violation and so cannot defeat the exigency.49