The Fourth Amendment to the Constitution guarantees “[t]he right of the people to be secure in their persons, houses, papers, and effects against unreasonable searches and seizures,” and requires that “no Warrants shall issue, but upon probable cause.” The “land immediately surrounding and associated with the home,” known as the curtilage, is considered part of the home for Fourth Amendment purposes. 

The Fourth Amendment requires, with some limited exceptions, that police officers have probable cause to suspect criminal activity and obtain a warrant from a federal magistrate judge before they are permitted to search a person’s home. To enforce this process, evidence gathered in violation of the Fourth Amendment is suppressed and may not be used at trial. In a typical scenario, the police search a criminal suspect’s property and find incriminating evidence that leads to the arrest and conviction of the individual. If this search of the home or curtilage is conducted without a warrant, it is presumed to violate the Fourth Amendment. The suspect’s remedy for the violation is the suppression of that evidence so that it cannot be presented at trial. Indeed, appellate courts will overturn convictions that depend on such evidence. To obtain a warrant, police must present an affidavit to a magistrate detailing both their reason for searching the person’s home and what they think they will find. If that affidavit demonstrates sufficient probable cause of illegal activity, the magistrate may issue the warrant, and evidence seized pursuant to a lawful warrant generally cannot be suppressed. This process of requiring police to obtain judicial approval before searching is generally considered sufficient to secure the home against unreasonable searches and seizures. The relative timing between obtaining the warrant and conducting the search is also important. Police cannot skirt the warrant requirement by entering the property without a warrant, collecting information, and then bringing the information found on the property before a magistrate as probable cause for a warrant. Anything found in the ensuing search can be suppressed. Evidence gathered from the defendant’s property but outside of his curtilage, however, falls beyond the scope of the Fourth Amendment and generally cannot be suppressed. Police can legally search this area—called the “open field”—without violating the Fourth Amendment, even if they are trespassing. Because the suppression remedy is generally only available for police action taken inside the home and curtilage, criminal trials often turn on where the curtilage line is drawn. Parties frequently appeal adverse curtilage decisions. In fact, defendants often plead guilty when trial courts deny motions to suppress but then appeal the denial. 

The circuits are divided over the correct standard for reviewing the trial court’s initial determination of the curtilage’s scope. Historically, all the circuits treated curtilage determinations as factual, reviewing them for clear error and granting broad deference to the trial judge’s findings. But now the First, Fourth, Ninth, and Tenth Circuits (“the de novo circuits”) review curtilage determinations de novo, while the Second, Third, Fifth, Sixth, Seventh, Eighth, and Eleventh Circuits (“the clear error circuits”) maintain clear error review.