Introduction

Testing a Search Warrant

Introduction

The second clause of the Fourth Amendment, usually called the Warrant Clause, sets the terms on which the government may obtain a court's permission to search: no warrant may issue "but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."¹ A search warrant is the resulting document, a judge's written order authorizing an officer to search a specified place and to seize evidence, and Federal Rule of Criminal Procedure 41 supplies the federal procedures for obtaining and carrying one out.² The clause places a judicial officer between the citizen and the police for a structural reason. An officer who is building a case has a stake in concluding that the case justifies a search, so the decision to enter a home is better made by someone with no stake in what the search turns up. In Katz v. United States the Court drew the consequence: the Constitution requires the deliberate, impartial judgment of a judicial officer before a search, and a search conducted without prior approval from a judge or magistrate is unreasonable in itself, subject only to a few specifically established exceptions.³

This chapter starts from the other end of that process, with a warrant the police already hold. Illinois v. Gates describes the Fourth Amendment's strong preference for searches conducted under a warrant, and one reason is that a warrant tells the person whose property is searched that the officer has lawful authority, that a search is needed, and where the officer's power stops.⁴ An occupant handed a signed warrant at the door who asks whether it is any good is asking what a court will later ask when that occupant, now a defendant, moves to exclude what the search produced. The answer comes in three checks, taken in order. The first asks what a warrant may be issued for and what sworn factual showing justifies it. The second asks whether the warrant itself describes the place to be searched and the things to be seized with the required particularity. The third asks whether the warrant was issued and executed as Rule 41 requires, which covers who issued it, where that person had authority, and how and when officers carried it out. A valid warrant must come from a neutral and detached magistrate, rest on probable cause shown by sworn facts, and particularly describe its targets, so a failure at any check undermines the whole.

Of the three, probable cause and particularity generate most of the real disputes. In searches for documents and other evidence, the usual difficulties are showing probable cause for each type of item the government hopes to find and then describing those items specifically enough.⁵ The chapter closes with what happens when a warrant fails, including suppression of the evidence, the good-faith doctrine that limits suppression, and the remedies that exist apart from it. Rule 41 leaves untouched any statute that regulates warrants in special circumstances, so what follows is the general federal framework.⁶ The probable-cause inquiry has a threshold that comes before it. Before asking whether the facts justify a warrant, a reader must know which categories of property and persons a warrant can reach at all, and the next section begins there, with the list of permitted objects in Rule 41(c).