4th Amendment

According to the Fourth Amendment, The right of people to be secure in their persons, houses, papers, against unreasonable searches and seizures shall no be violated and no warrants shall issue, but upon reasonable cause supported by Oath or affirmation and particularly describing the place to be searched and the persons or things to be seized.

Protection from unreasonable searches and seizures requires police, if they have time to obtain a valid search warrant, issued by a magistrate after the police indicate under oath that they have probable cause to justify its issuance. Magistrates must perform this function in a neutral and detached manner and not serve merely as rubber stamps for the police. The warrant must specify the place to be searched and the things to be seizes. General search warrants are warrants that authorize police to search a particular place or person without limitation are unconstitutional. A search warrant is usually needed to search a person in any place he or she has an expectation of privacy that society is prepared to recognize as reasonable.

Police may make reasonable warrantless searches in public places if the officers have probable cause, or suspicion, that the person in question have committed or are about to commit crimes. No later than two days after making such an arrest the police must take the arrested person to a magistrate so that the magistrate can decide whether probable cause existed to justify a warrantless arrest of people in they own homes.

The Fourth Amendment requires that a se

Under common law police officers apprehending a fleeing suspected felon can us weapons that might result in the felon's serious injury or even death. But the Fourth Amendment places substantial limits on the use of what is called deadly force. It is unconstitutional to shoot an apparently unarmed, fleeing suspected felon unless the officer has probable cause to believe that the suspect poses a significant threat of death or serious injury to the officer or others.

Not every time the police stop a person to ask questions or to seek that person's consent to a search is there a seizure or detention requiring probable cause or a warrant. If the police just as questions or seek consent to search an individual person or possessions in a no coercive atmosphere, there is no detention. If the person refuses to answer questions or consent to a search, and the police by either physical force or a show of authority, restrain the movement of the person, even though there is no arrest, the Fourth Amendment comes in play.

The Supreme Court upheld in Terry v. Ohio (1968), a stop and frisk exception to searches of individuals when officers have reason to believe they are armed and dangerous or have committed a criminal offense. The Terry search is limited to a quick pat down to check for weapons that might be use to assault the arresting officer, to check for contraband, to determine identity, or to maintain the status quo while obtaining more information. Police and border guards may conduct border searches, the searches of persons and goods they bring across borders. The border search exception permits officials to open mail entering the country if they have reasonable cause to suspect it contains merchandise imported in violation of the law.

There are several other exceptions to the general rule against warrantless searches and seizures of what is found by police and customs officials. The most important are the plain view exception, exigent circumstances, and automobile exception. The Plain-View exception permits officers to seize evidence without a warrant if they are lawfully in a position from which the evidence can be viewed, it is immediately apparent to them that the items they observe are evidence of a crime or are contraband, and they have probable cause to believe