A Super-Brief Overview of the Fourth Amendment

Fourth Amendment doctrine is a fairly complex and seemingly arcane area of constitutional and criminal law, and I will post a condensed and simplified version of it here. The U.S. Supreme Court has issued a recent decision in Byrd v. United States that has established a new rule for this issue, and so now is as good a time as any to offer a primer. (The decision, in essence, holds that someone who is driving a rental car but is not a listed driver on the rental contract still has a right to be free from police searches inside the vehicle without consent or a warrant.)

The Fourth Amendment to the U.S. Constitution, which is binding on all state governments through application of the due process clause, protects people from “unreasonable” searches and seizures by government officials and requires warrants to be specific and supported by probable cause. (Maine’s constitution has a parallel protection, but for reasons that I don’t understand the state supreme court refuses to give the people any greater protection because of it.) A search can be of someone’s clothing, home, personal vehicle, cell phone, blood sample, etc. A seizure can be an arrest or a detention that resembles an arrest but doesn’t last as long, such as a stop for a traffic violation. A detailed warrant that is supported by probable cause and signed by a judge generally makes a search or seizure constitutional, whereas an arbitrary seizure or a random search is generally unconstitutional. In between these obvious extremes are the gray-area cases where concepts like (supposed) consent to search, reasonable articulable suspicion, “inevitable discovery” doctrine, and reasonable expectation of privacy become relevant.

So, let’s say that the Bangor Police Department executed a search of a criminal suspect’s home without a warrant, and none of the other rules seems to apply to exempt the police from the so-called warrant requirement — lawyers often say the exceptions have swallowed the rule. If the prosecution wants to use any of the illegally obtained evidence in a criminal case against the suspect-turned-defendant, the defendant or defense attorney then writes and files a motion to suppress. A judge then hears testimony, considers the parties’ arguments, and determines whether this evidence has been tainted. If it has been tainted by a constitutional violation, it will not be admissible at trial under the exclusionary rule; however, it may be used at other proceedings, such as probation revocation hearings.

The exclusionary rule may seem unfair to certain people who think an accused criminal shouldn’t be able to skate just because law enforcement officers didn’t get a search warrant, but by deterring misconduct this due process rule protects all of us (not just criminal defendants) to some extent from governmental intrusions on our private lives and governmental seizures of our bodies.