Imagine that the police entered someone's home completely randomly without proper authorization and searched every corner of the house. By chance, they stumbled upon a murder scene. In this situation, would the evidence they collected be allowed to be used in court?

Would the judicial system overlook the police's violation of protocol? Would they dismiss the entire case out of a strict adherence to proper procedure? Or would it be up to the discretion of whichever judge happened to be sitting on that day?

  • 7
    Near-duplicate: How far does the fruit of the poisonous tree doctrine extend?
    – sjy
    Dec 12, 2022 at 15:21
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    Pragmatically, assuming the police went 100% undetected, an experienced officer would quickly work backwards to legally acquire a search warrant for something unrelated and then "stumble" upon this murder evidence.
    – MonkeyZeus
    Dec 12, 2022 at 16:09
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    If you're trying to research MonkeyZeus's comment, the keywords to look for are "Parallel Construction" and "evidence laundering." Due to supreme court precedent (discussed in sjy's link above), such evidence may be accepted even when the "stumble" was admittedly based on the original, illegal evidence.
    – Brian
    Dec 12, 2022 at 16:22
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    Even if they couldn't use that evidence in court, I bet the police would immediately start some sort of process to legally obtain as much evidence as they could. New, legally admissible, evidence would likely be obtained pretty quickly.
    – user4574
    Dec 12, 2022 at 16:57
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    It seems unlikely that they would choose a house to search "randomly". Much more plausible is that they would search a house for a spurious reason, or search the wrong house. They would have some explanation for their actions (e.g. a neighbour thought they heard someone screaming), and that explanation might well have relevance to the question. Dec 13, 2022 at 15:39

3 Answers 3


There are some complexities here, and several possibilities.

First of all, it seems from the question that:

  1. There were not any "exigent circumstances" or any other special situation which would justify making a search without a warrant (there are several circumstances which can justify a warrantless search, but none are mentioned in the question).
  2. The police had no probable cause, indeed not even any reasonable suspicion. Thus the police had no valid reason even to request a warrant, and if they had asked for one, they should have been refused.
  3. No resident of the house consented to any search at any point.
  4. The police had no honest belief that they were acting lawfully. They knew, or any reasonable police officer should have known, that they were acting unlawfully.

Now, let us consider some of the possibilities left open by the question. For purposes of discussion, let us assume that the house was owned by Bob and Carol, and no one else lived in it. There are several possibilities.

Case One: The evidence appears to implicate Bob. Bob is charged, and Bob's lawyer Joan makes a timely motion to suppress the evidence. The judge should hold a suppression hearing, and under these conditions, should suppress the evidence. The trial will go forward without it, or be dismissed if there is not enough other evidence to proceed.

Case Two: Much like Case One, but another group of police officers had good reason to suspect Bob, and was already in the process of preparing a request for a warrant, supported by valid probable cause. Had the first group not searched the house unlawfully, the second group would have obtained a valid warrant and found the evidence under its authority. In this situation, known as inevitable discovery the evidence would be admitted, and the unlawful search will not matter.

Case Three: The evidence implicates Fred, not Bob or Carol. Fred did not live in the house, but had asked Carol to store some boxes for him. Carol did not know what was in them. Fred has no privacy rights to the house. Bob or Carol could have lawfully consented to a search, and Fred would have no grounds to object. Fred has no grounds to suppress the evidence, as Fred's rights were not violated, and Fred cannot assert Bob or Carol's rights. A trial of Fred would proceed as if the search had been lawful. Bob and Carol may have grounds for a Section 1983 lawsuit against the police for violation of their rights, but that will not help Fred.

Case Four: The evidence appears to implicate Bob. The police arrest Bob, and tell him that they have a case against him, and that if he does not confess, they will also arrest Carol as an accomplice. (They lie, but Bob believes them.) Bob pleads guilty. The unlawful search is never raised, and Bob is sentenced as if it had been lawful.

Case Five: The evidence appears to implicate Bob. Bob's lawyer Joan fails to request a suppression hearing, or to object at trial to the evidence from the unlawful search. Or more likely, instead of going to trial, Bob's lawyer arranges a plea bargain without raising the issue of the search. Bob is convicted as if the search had been lawful. Bob may have a valid appeal on the grounds of ineffective assistance of counsel, as Joan should have known better.

Case Six: The evidence appears to implicate Bob. But the police have other evidence as well. Bob's lawyer raises the issue of the unlawful search. However, the prosecutor convinces Bob's lawyer Joan that they can probably convict Bob even without the evidence from the search. Joan arranges a plea bargain, and Bob accepts it. Bob will be sentenced under the plea deal, and nothing will be done about the unlawful search, except that Bob may get a somewhat better deal because the authorities do not want it exposed in court.

Note that only in cases One and Five will a possibly guilty person possibly go free because of the unlawful search, and it is by no means certain even there.

It is also possible that a judge will wrongly admit the evidence in a Case One situation. This is likely to be corrected on appeal, with the unlawfulness as blatant as the question assumes. In a case where the unlawfulness is more marginal, this is less sure.

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    Case 4 sounds like coercion to me.
    – Neil Meyer
    Dec 13, 2022 at 16:59
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    @NeilMeyer Almost everything the police do to elicit testimony is coercive, the question is whether it's unlawfully coercive. In the US, police are allowed to lie to a suspect to elicit testimony, which is not true in every country. Keep in mind though that suspects in the US have an absolute right to refuse to say anything to police and that can't be held against them if they invoke it, which is also not true in every country. Dec 13, 2022 at 20:42
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    @IllusiveBrian Case Four is indeed coercive, and many would call it unethical. But US courts have held such tactics to be lawful. That is not true in some other countries. A separate question about this would properly be answered with case law on this specific point, that is too much for a comment, IMO. Dec 13, 2022 at 21:59
  • @NeilMeyer yes, because the US police has not really been kept in check or ever truly been checked to uphold civil liberties or rights
    – Hobbamok
    Dec 15, 2022 at 13:52
  • @IllusiveBrian I wouldn't say absolute right. First, you are required to speak up and explicitly assert the right in order to benefit from it (so absolute silence can be held against you); seems wild that a right to remain silent demands non-silence. And there are all sorts of ways that questioning can be resumed or continued after trying to invoke the right; if you invoke it a little too late after saying something, if you just speak up of your own volition, etc. There are whole complicated flow charts governing the "right to remain silent". Dec 19, 2022 at 12:33

Without more information, and given your assertion that the entry was "completely random[]" (i.e. without determination that exigent circumstances required entry) and without a warrant, then this would be a Fourth Amendment violation of those that had a privacy interest in that home.

Here's why:

  • the home and the body are the areas in which a person has the greatest expectation of privacy (the Katz standard)
  • entry into the home is also a trespass (which would make this a search under the Jones standard)
  • people are protected from unreasonable searches and seizures; generally, this means that they must be supported by a warrant unless falling within an exception to the warrant requirement; in all cases the search must not be unreasonable
  • given your assertion that the entry was "completely random[]" this would be the epitomy of an unreasonable search

Assuming that the person they would be charging had a privacy interest in that home (this is the critical assumption in my answer), and assuming the accused brings a motion to supress, the evidence would almost certainly be excluded at trial. In the circumstances you've described, and assuming no further circumstances relating to the evidence or how it might have been obtained, you have left no room for discretion. If the judge declined to exclude the evidence, it would be an error of law, and I have no problem predicting that any conviction relying on that evidence would be overturned on appeal.

Whether the case can proceed without the evidence that was obtained as a result of the Fourth Amendment violation depends on the specifics of the case. Exclusion of evidence does not necessarily doom the prosecution to fail, but where critical evidence such as what you've described is excluded, this would likely be the end of the state's case.

  • What if they didn't have any warrants, but gave a plausible reason like "something smelled funny through an open window while I was on patrol"?
    – AlanSTACK
    Dec 12, 2022 at 0:53
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    @AlanSTACK is your question about how a criminal investigation can proceed after a fourth amendment violation or is it about the circumstances under which a search would or would not violate the fourth amendment? These are two very different questions.
    – phoog
    Dec 12, 2022 at 1:04
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    @AlanSTACK the appropriate place to ask such questions is in a question - not in a comment on an answer to another question.
    – Dale M
    Dec 12, 2022 at 8:26
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    @AlanSTACK You want to look up "exigent circumstances". Dec 12, 2022 at 10:38
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    @11684 See Case Two of my answer. Such lawful way to find the evidence would usually make it admissible, if that way was not tainted by the earlier unlawful search. Dec 12, 2022 at 14:27

In this situation, would the evidence they collected be allowed to be used in court?

As Jen explains, generally not.

Would the judicial system overlook the police's violation of protocol?


Would they dismiss the entire case out of a strict adherence to proper procedure?

Only if the police and prosecutor were unable to develop additional evidence establishing someone's guilt. (Note that in the hypothetical there is no evidence pointing to any particular perpetrator, so the hypothetical as given doesn't even necessarily lead to a trial.)

Or would it be up to the discretion of whichever judge happened to be sitting on that day?

Generally not. Exclusion of improperly obtained evidence is not a matter of discretion.

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