Fourth Amendment Protection Against Unreasonable Searches and Seizures

The law addressing governmental searches and seizures is both complicated and extensive. At common law, the government could perform warrantless searches. The Bill of Rights, including the Fourth Amendment, changed that. A search warrant is required in most cases.

The U.S. Supreme Court has interpreted and clarified the Fourth Amendment protection throughout American history. It has answered the following questions, among others:

• When does a law enforcement officer's search constitute an illegal search?
• When must police officers comply with the search warrant requirement?
• When, if ever, are warrantless searches permitted?
• What happens if the government illegally searches one's property or person?

This article summarizes the Fourth Amendment protection against unreasonable searches and seizures. If you are facing criminal charges, you can also contact an attorney in your area for targeted legal advice. A criminal defense attorney can review the circumstances of any searches, seizures, or arrests to determine if they violated your Fourth Amendment rights. This can be crucial for your defense strategy. 

The Fourth Amendment's Text

"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but 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 Fourth Amendment Explained

The Fourth Amendment to the U.S. Constitution protects against unreasonable governmental searches. This includes searches by:

• Police officers
• FBI agents
• State troopers
• Other law enforcement officials

But, the protection only applies if you have a reasonable expectation of privacy in the place or subject searched.

The Fourth Amendment doesn't prevent all searches by government agents. The police can still search or seize when they have a valid search warrant, a valid arrest warrant, or probable cause that a person committed a crime.

An unreasonable search may occur in several different ways. For example, the search is likely illegal if the government does not get a valid search warrant. A search is also likely unlawful if the government does not have probable cause to believe that the person or place to be searched was involved in criminal activity. If the government oversteps the search warrant's bounds, it is likely an unreasonable search.

Search Warrants and Probable Cause

The government typically performs a valid search after getting a search warrant. Although there are exceptions to the search warrant requirement, most searches require one.

Law enforcement obtains a search warrant by requesting one from a judge or magistrate. Law enforcement must typically file an affidavit establishing probable cause. To do so, they must show the following:

• That the police officer is aware of certain circumstances, facts, or knowledge, either personally or via a reasonably trustworthy source
• That a reasonable person aware of the facts, circumstances, or knowledge would believe a criminal offense had been committed or is about to occur

The judge or magistrate will review the affidavit and analyze the situation. Then, they will either issue or deny the search warrant.

The search warrant identifies the person or places the government may search. For example, it may specify the attic of the suspect's home. It also determines the search's time and manner. If law enforcement's search goes beyond the warrant's scope, it is likely an illegal search.

Exceptions to the Warrant Requirement

The government can perform valid warrantless arrests, searches, and seizures in certain situations. These situations include the following, among others:

• With the owner's consent
• Under exigent circumstances
• During a search incident to a lawful arrest
• During a stop and frisk, also known as a Terry stop, from Terry v. Ohio (1968)
• Under the plain view exception

Review the annotations below for more detailed information on exceptions to the warrant requirement. Alternatively, consider contacting a criminal defense attorney near you.

The Exclusionary Rule

Search and seizure rules generally determine whether evidence is admissible at trial. The criminal trial will bar any evidence collected in a manner that violates the Fourth Amendment. This is known as the exclusionary rule.

The colorfully named fruit of the poisonous tree doctrine also bars evidence from trial. The doctrine refers to the court's exclusion of evidence the government derived from an illegal search.

For example, suppose law enforcement searches a homeowner's house without a valid warrant, and no exceptions apply. During the illegal search, law enforcement finds contraband. They also find a computer containing the locations of various drugs and weapons. Suppose the police visit these locations and seize the drugs and weapons.

At the criminal trial, the prosecution attempts to admit the contraband officers found at the defendant's home, along with the drugs and weapons they seized. Because the initial search of the home was illegal, the exclusionary rule bars the contraband's admittance at trial. Additionally, the fruit of the poisonous tree doctrine bars the court from admitting the drugs and weapons into evidence.

Fourth Amendment: Annotations and Articles

The following articles will help you better understand how the courts have interpreted the Fourth Amendment.

History and Scope of the Fourth Amendment

The Fourth Amendment has a rich history in United States jurisprudence. The Scope of the Rights Protected by the Fourth Amendment annotation provides information about this history. The article covers both pre- and post-American Revolution jurisprudence regarding searches and seizures. It also details the Fourth Amendment's scope and the specific interests it protects. Further, it discusses the Fourth Amendment's application to arrests and other detentions and searches in noncriminal cases.

For more context, see the following:

• Fourth Amendment Search and Seizure Protections
• Summary of the Fourth Amendmentm
• When Is an Arrest a Legal Arrest?

Learn more about the Fourth Amendment in FindLaw's U.S. Constitution section.

Searches and Seizures Pursuant to Warrant

A reasonable search typically requires probable cause or a valid warrant. FindLaw's article Fourth Amendment Seizures of Property details search warrant requirements as they relate to specific industries subject to regular administrative searches. For more information about search warrants, see the following:

• Probable Cause

A neutral judge or magistrate determines whether to issue a search warrant. They based their decision, in part, on whether probable cause exists regarding criminal activity. Thus, it is important to understand the relationship between probable cause and search warrants.

The Warrant Requirement Explained

Understanding the search warrant requirement is crucial for criminal defendants. The Need for a Warrant to Conduct a Search or Seizure summarizes the warrant requirement. Specifically, it describes who can issue a warrant, how a judge determines probable cause, and the particularity requirement. For more information about the warrant requirement, see the following:

• Search Warrant Requirements
• When the Fourth Amendment Applies

As noted above, the search warrant must specify the parameters of the search with particularity. If a court determines the warrant is insufficient, the search is illegal. However, the good faith exception may protect officers who believed the warrant was valid.

Probable Cause

At the heart of most searches and arrests is probable cause. The U.S. Supreme Court has wrestled with what constitutes probable cause many times in its history. Supreme Court Interpretation of Probable Cause provides an in-depth summary of probable cause. Among other topics, this annotation covers probable cause established through private investigators. It also discusses the interplay between the First Amendment and probable cause.

Seizures of Persons Without a Warrant

Law enforcement must typically show probable cause and obtain an arrest warrant to arrest a person legally. The Fourth Amendment protects people from unreasonable searches and arrests alike. Fourth Amendment Seizure of Persons discusses arrest warrants, search warrants, and some exceptions to the warrant requirement.

Valid Searches and Seizures Without a Warrant

There are numerous exceptions to the Fourth Amendment's warrant requirement. Exceptions to the Fourth Amendment Warrant Requirement describes a number of these exceptions. It also details the Fourth Amendment's application to law enforcement's arrest of a person. For more information on the exceptions, see the following:

• Vehicle Searches Under the Fourth Amendment
• What Is Stop and Frisk?
• Strip Search After an Arrest
• School Searches and Weapons

For more information on exceptions, browse FindLaw's Criminal Rights section.

Electronic Surveillance and the Fourth Amendment

The Founding Fathers could not anticipate the depth of technological advancements since the Constitution's ratification. At its inception, the Fourth Amendment did not consider electronic surveillance, such as wiretaps. The Supreme Court has interpreted and applied the Fourth Amendment to situations where the government electronically surveilled a person or place. Generally, law enforcement must obtain a search warrant to surveil a subject electronically.

For more information about these searches, see the following:

• Olmstead v. United States (1928)
• Berger v. New York (1967)
• Katz v. United States (1967)
• Cellphone Privacy and Warrant Requirements
• Do the Police Have the Right to Tap My Telephone?

As technology continues to advance, litigation will surely follow. The Supreme Court will certainly hear more Fourth Amendment cases tied to to changing technology. It is important to understand your privacy rights and whether you have a reasonable expectation of privacy.

Enforcing the Fourth Amendment: The Exclusionary Rule

As noted above, the exclusionary rule bars illegally obtained evidence from being admitted in a criminal trial. The Exclusionary Rule: How Fourth Amendment Violations Can Lead to Tossed Evidence describes the Fourth Amendment's exclusionary rule in depth.

Specifically, it details the rule's development, foundations, and its narrowing application. For more information about the exclusionary rule and fruit of the poisonous tree doctrine, see the following:

• The Fourth Amendment and the Exclusionary Rule

Learn More About the Fourth Amendment by Talking to a Lawyer

The Fourth Amendment is packed with rights and protections. To learn more about your rights or to get help fighting criminal charges, contact a skilled criminal defense attorney in your area today. An experienced attorney can help you with the following:

• General information about criminal law and criminal cases
• Your individual rights granted by the U.S. Constitution
• Whether the government's seizure of evidence of a crime was legal
• State laws affecting your criminal case

If you are involved in a criminal case or believe the government illegally searched your person or property, consider contacting a criminal defense lawyer near you.