Fourth Amendment: Search for Lawful Seizures

The Passage

The Fourth Amendment was passed along with nine others that together became known as the Bill of Rights in 1791. There was a huge concern that without written rights, the national government would obtain too much power and become oppressive. British authorities routinely abused their power to take colonists' goods and property, so the Fourth Amendment was created to prevent this new government from doing the same.

Amendment 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.

What Does It Mean? 

The Fourth Amendment prevents government authorities from unlawfully searching or taking citizens’ property. The police usually conduct searches and seizures. For these actions to be lawful, they must first obtain a warrant signed by the proper government official. The Fourth Amendment presents the framework for obtaining a search warrant. The Fourth Amendment explicitly states that in order to enter a home, the government authority must have probable cause and be able to prove such in a court of law. Hunches and suspicions aren’t good enough - a warrant can only be issued if there is convincing evidence that a crime was or is underway. A judge usually decides if this standard of probable cause has been met when a warrant is issued. Warrants grant officers the authority to make an arrest, seize property, search property, or carry a judgment into execution. It is important to note that warrants specify who and what they apply to, and officers cannot go beyond a warrant's original purpose under normal circumstances.

However, the Fourth Amendment doesn’t mean that the police always need a warrant to conduct a search. There are still various acceptable situations for legal warrantless searches by law enforcement officers and can be categorized into safety checks and “plain view or feel.” Officers are allowed to check a person if they see evidence of criminal activity or feel, during a lawful pat-down, some contraband. Furthermore, if an individual consents, then the police may legally search the individual.

Major Court Cases

The Supreme Court enforced the exclusionary rule, which prohibits the use of illegally obtained evidence in a criminal trial, in Mapp v. Ohio in 1961. As a result of the case, the Supreme Court declared that all evidence obtained from searches and seizures in violation of the Fourth Amendment is invalid in a state court. Thus, police officers have to follow all constitutional procedures to get evidence permitted, and perhaps confirm a conviction. 

The Court also determined that schools can place restrictions on students' Fourth Amendment rights. In 1995, Vernonia School District v Acton ruled public school officials may conduct reasonable warrantless searches of their students. This standard was further lowered in 2002 with the decision of Pottawatomie v. Earls: given the special needs of a school environment, suspicionless searches could be carried out. 

Terry v. Ohio, a 1968 Supreme Court case, held that law enforcement officers were permitted to stop and frisk a person on the street if they had a “reasonable” belief that the person may be armed, or under suspicion that the person has committed, is committing, or is about to commit a crime. This case lowered the standard for searches and seizures by law enforcement officers from “probable cause,” which is stated in the Fourth Amendment, to “reasonable suspicion.” 


The definition of the terms "unreasonable" and "probable cause" has sparked significant debate given their subjectivity. Critics worry that the standard for reasonableness gives government authorities leeway to abuse their power. Terry v. Ohio raised concerns because lowering the standards to stop and frisk to “reasonable belief” allowed police officers more subjective freedom and introduced concerns about the implicit racial biases associated with these searches. Proponents of stop and frisk policies discredit these biases by arguing that individuals who are adhering to the law should have no concerns. 

The Fourth Amendment is often subjected to scrutiny because Black and brown citizens are subject to searches and seizures at higher rates than white citizens. According to the 2011 NYPD statistics on Stop and Frisk, people of color are stopped and searched by police at higher rates than white people despite committing crimes at equal levels. A central demand of the Black Lives Matter and police reform movements is equal protection under the law in regards to searches and seizures.

With evolving technology, the Supreme Court has leaned toward protecting an individual’s privacy. Kyllo v. United States in 2001 made it illegal for the government to use any device not in public use, like thermal imaging devices, to search the inside of a home in a way that would otherwise require physical intrusion. The case raised the question of how new technologies may aid government intrusion into the privacy of the home and further their search and seizures. In addressing similar concerns, the Court unanimously ruled in 2014 during Riley v. California that a warrantless cell phone search on a vehicle was illegal. The Court argued that cell phones hold significant private information and this type of digital data cannot be used in an arrest. Proponents of these new technologies appreciate the added protections, while adversaries of them lament that these methods are an invasion of privacy. 

Why Care?

The Fourth Amendment provides citizens the right to be secure in their persons, property, and homes. Without it, the government would have unchallenged access to the personal lives of individual people. The right to privacy is fundamental in a democracy, and it’s a right we’re still fighting for. Racial injustices continue to plague our American democracy. Whenever the government oversteps its authority, make your voice heard. The essence of the Fourth Amendment is preserving personal privacy, and everyone needs to fight to maintain their protections.

Think Further

  1. What do “unreasonable” and “probable cause” mean to you in the context of the Fourth Amendment?
  2. What rights to privacy do you have in different spaces? At home? In a car? At school?
  3. Can you think of a court case not discussed that involves the Fourth Amendment? What was it? Why was it important?


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Learn More

  1. “Cases- Search and Seizure.” Oyez,
  2. “Fourth Amendment.” Legal Information Institute, Cornell Law School,
  3. Rosenthal, Lawrence. “Binary Searches and the Central Meaning of the Fourth Amendment.” SSRN, Chapman University, The Dale E. Fowler School of Law, 10 Oct. 2013,
  4. Zotti, Priscilla Machado. Injustice for All: Mapp vs. Ohio and the Fourth Amendment. P. Lang, 2005.
  5. “Census Bureau.” Table DP-1. Profile of General Demographic Characteristics: 2000, Geographic area: New York City, New York.