Criminal Procedure

Criminal prosecutions officially begin with an arrest. However, even before the arrest, the law protects the defendant against unconstitutional police tactics. The Fourth Amendment protects persons against unreasonable searches and seizures by law enforcement officers. Generally, a SEARCH WARRANT is required before an officer may search a person or place, although police officers may lawfully prevent a criminal suspect from entering his or her home while they obtain a search warrant. Illinois v. McArthur, U.S. 326, 121 S. Ct. 946, 148 L. Ed. 2d 838 (2001).

Police officers need no justification under the Fourth Amendment to stop persons on the street and ask questions, and persons who are stopped for questioning are completely free to refuse to answer any such questions and to go about their business. But the Fourth Amendment does prohibit police officers from detaining pedestrians and conducting any kind of search of their clothing without first having a reasonable and articulable suspicion that the pedestrians are engaged in criminal activity. The U.S. Supreme Court has held that reasonable suspicion is provided for a stop-and-frisk type of search when a pedestrian who, upon seeing police officers patrolling the streets in an area known for heavy narcotics trafficking, flees from the officers on foot. Illinois v. Wardlow, 528 U.S. 119, 120 S. Ct. 673, 145 L. Ed. 2d 570 (2000)

The warrant requirement is waived for many other searches and seizures as well, including a search incident to a lawful arrest; a seizure of items in plain view; a search to which the suspect consents; a search after a HOT PURSUIT; and a search under exigent or emergency circumstances. Nor does the Fourth Amendment require the police to obtain a warrant before seizing an automobile from a public place when they have probable cause to believe that the vehicle is forfeitable contraband. Florida v. White, 526 U.S. 559, 119 S. Ct. 1555, 143 L. Ed. 2d 748 (1999).

However, the Fourth Amendment does prohibit police use of a thermal-imaging device aimed at a private home from a public street to detect relative amounts of heat within the home. Such devices are typically employed to determine whether a suspect is using a high-intensity lamp to grow marijuana in his or her home. The U.S. Supreme Court has ruled that the use of thermal-imaging devices constitutes a "search" within the meaning of the Fourth Amendment, and thus their use is presumptively unreasonable without a warrant. Kyllo v. United States, 533 U.S. 27, 121 S. Ct. 2038, 150 L. Ed. 2d 94 (2001).

The Supreme Court also ruled that a state hospital conducted an unreasonable search when it undertook warrantless and nonconsensual urine testing of pregnant women who had manifested symptoms of possible cocaine use. The governmental interest in using the threat of criminal sanctions to deter pregnant women from using cocaine did not justify a departure from the general rule that an official nonconsensual search is unconstitutional if not authorized by a valid search warrant. Ferguson v. City of Charleston, 532 U.S. 67, 121 S. Ct. 1281, 149 L. Ed. 2d 205 (2001).

The U.S. Supreme Court's Fourth Amendment JURISPRUDENCE is splintered over the constitutionality of using fixed checkpoints or roadblocks to conduct warrantless and suspicionless vehicle seizures. The Court has held that the Fourth Amendment allows law enforcement to perform warrantless vehicle seizures at a fixed checkpoint along the nation's border to intercept illegal ALIENS, so long as the search is reasonable in light of the "totality of the circumstances". United States v. Arvizu, 534 U.S. 266, 122 S. Ct. 744, 151 L. Ed. 2d 740 (2002). The Court also ruled that roadblocks may be used to intercept drunk drivers. However, the Court rejected on Fourth Amendment grounds the use of a roadblock to perform warrantless and suspicionless searches of automobiles for the purpose of drug interdiction. Indianapolis v. Edmond, 531 U.S. 32, 121 S. Ct. 447, 148 L. Ed. 2d 333 (2000).

When an officer seeks a search warrant, he or she must present evidence to a judge or magistrate. The evidence must be sufficient to establish probable cause that evidence of a crime will be found at the place to be searched. Probable cause is a level of belief beyond mere suspicion but short of full certainty. Whether an officer can establish probable cause to obtain a search warrant depends on the facts of the case. For example, if an arrested person is discovered with a small amount of marijuana, this alone will not justify a search of the person's home. However, if the person is discovered with a large amount of marijuana, the quantity may support the suspicion that more marijuana may be found in the person's home, and the large amount may be used as the basis for obtaining a search warrant.

Police officers seeking a search warrant must state, under oath and with particularity, the facts supporting probable cause. If the search warrant is later found to be lacking in probable cause, or if important statements made by the officers are found to have been intentionally misleading, the evidence seized pursuant to the warrant might not be admissible at trial. Moreover, if the search goes beyond the scope granted in the warrant, the evidence seized as a result of that encroachment might not be admissible at trial. For example, if the warrant states that the officers may search only the suspect's apartment, they may not expand the search to a storage closet outside the apartment.

In executing a search warrant pursuant to the Fourth Amendment, law enforcement officers may enter private property without knocking or announcing their presence if the officers have reasonable suspicion that knocking and announcing would be dangerous, futile, or would inhibit an effective criminal investigation by allowing the destruction of evidence. While the lawfulness of a "no-knock" entry does not depend on whether property is subsequently damaged during the search, excessive or unnecessary destruction of property in the course of the search might violate Fourth Amendment rights, even though the entry itself is lawful and the fruits of search are not subject to suppression. United States v. Ramirez, 523 U.S. 65, 118 S. Ct. 992, 140 L. Ed. 2d 191 (1998).