Search and seizure

Search and seizure is a legal procedure used in many common law countries whereby police or other authorities and their agents, who suspect that a crime has been committed, do a search of a person's property and confiscate any relevant evidence to the crime. Certain countries, such as the United States and Canada, have provisions in their constitutions that provide the public with the right against "unreasonable" search and seizure. This right is generally based in the premise that everyone is entitled to a reasonable right to privacy.

Though interpretation may vary, this right usually requires law enforcement to obtain a search warrant before engaging in any form of search and seizure.

United States

The Fourth Amendment to the United States Constitution ensures citizens' right to "be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures …" The amendment goes on to set forth the conditions under which a warrant may be issued: "upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." The text of the amendment is brief, and most of the law determining what constitutes an unlawful search and seizure is found in court rulings. The general rule under the U.S. Constitution is that a valid warrant is required for a valid search. There are, however, several exceptions to this rule.

For instance, the owner of the property in question may consent to the search. The consent must be voluntary, but there is no clear test to determine voluntariness; rather, a court will consider the "totality of the circumstances" in assessing whether consent was voluntary. Police officers are not required to advise a suspect that he may refuse. There are also some circumstances in which a third party who has equal control, i.e. common authority, over the property may consent to a search.

When an individual does not possess a "reasonable expectation of privacy" that society is willing to acknowledge in a particular piece of property, any interference by the government with regard to that property is not considered a search for Fourth Amendment purposes, and a warrant is never required. For example, courts have found that a person does not possess a reasonable expectation of privacy in information transfered to a third party, such as writing on the outside of an envelope sent through the mail or left for pick-up in an area where others might view it. While that does not mean that the person has no reasonable expectation of privacy in the contents of that envelope, the Court has held that one does not possess a reasonable expectation of privacy that society is willing to acknowledge in the contents of garbage left outside the curtilage of a home. There is also a lowered expectation of privacy inside of a motor vehicles. A 'bright line' has been drawn at the doorstep of person's homes, however, so that whenever the government intrudes inside, their action is considered a search for Fourth Amendment purpose and must always be accompanied by a search warrant (absent exigent circumstances).

Courts have also established an "exigent circumstances" exception to the warrant requirement. "Exigent circumstances" simply means that the officers must act quickly. Typically, this is because police have a reasonable belief that evidence is in imminent danger of being removed or destroyed. Exigent circumstances may also exist where there is a continuing danger, or where officers have a reasonable belief that people in need of assistance are present.

Certain limited searches are also allowed during an investigatory stop or incident to an arrest. These searches are called Searches incident to a lawful arrest.

While the interpretations of the U.S. Supreme Court are binding on all state and federal courts interpreting the U.S. Constitution, there is some variance in the specifics from state to state, for two reasons. First, if an issue has not been decided by the U.S. Supreme Court, then a lower court makes a ruling of "first impression" on the issue, and sometimes two different lower courts will reach different interpretations. Second, virtually all state constitutions also contain provisions regarding search and seizure. Those provisions cannot reduce the protections offered by the U.S. Constitution, but they can provide additional protections such that a search deemed "reasonable" under the U.S. Constitution might nonetheless be unreasonable under the law of a particular state.

The primary remedy in illegal search cases is known as the "exclusionary rule". This means that any evidence obtained through an illegal search is excluded and cannot be used against the defendant at trial. There are some narrow exceptions to this rule. For instance, if police officers acted in good faith--perhaps pursuant to a warrant that turned out to be invalid, but that the officers had believed valid at the time of the search--evidence may be admitted.

Further, under the "fruit of the poisonous tree" doctrine, additional evidence discovered as a result of illegally obtained evidence is also excluded.

http://en.wikipedia.org/wiki/Search_and_seizure