The Fundamentals of the Fourth Amendment – Part 1 – Q1 2024 Facts & Findings

As a paralegal for the public defender’s office, this is a precious amendment to our clients who feel their Fourth Amendment rights have been violated. One of the most important, yet misunderstood, legal principles of American jurisprudence is the Fourth Amendment. Many people do not understand what their Fourth Amendment rights entail, when and how they can assert them, and in what circumstances Fourth Amendment rights are being infringed. The Fourth Amendment can be complex, but it is important to become familiar with it.

Search and arrest warrants find their origins in English common law. Search warrants, which can be traced back to as early as the 16th century, were considered “special” warrants. The victim of a crime had to go before a justice of the peace, testify under oath with particularity as to the crime (such as by describing the goods that were stolen and when and how they were stolen), and then the victim could go with the constable to recover the goods and bring the accused with the goods to a justice of the peace for disposition of the matter.1

Of course, an arrest warrant was a command to the sheriff of a county or marshal of a court to apprehend a felon and bring him to court. Another category of warrants, and probably the most controversial, were writs of assistance. These writs were general warrants, which required no particularized showing of wrongdoing. These were absolute, unlimited, and permanent warrants for customs officials to search at their discretion. Writs of assistance were primarily a means to combat smuggling, especially in the American colonies.

New writs of assistance that were requested in 1760 prompted a group of Boston merchants to oppose the proposed writs. These merchants retained James Otis to represent them. Otis argued that the Superior Court should not continue to grant the writs in general and open-ended form. Rather, it should be limited to particularized suspicion based on the circumstances. Although Otis and the Boston merchants lost the case, this became a major turning point for the American Revolution and, ultimately, the formulation of the Fourth Amendment.

The Fourth Amendment provides:

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.

A multitude of case law has been developed over the last century to interpret this amendment. The starting place for any Fourth Amendment analysis is whether there is government action. If there is government action, the next step is to determine whether the government intrusion rises to the level of a search, as not all government encounters are searches and seizures for Fourth Amendment purposes. If an action is not a search or seizure under the Fourth Amendment, no warrant is necessary, and no further analysis is needed.

Finally, if there is a government search or seizure, it must be determined whether probable cause existed for the government intrusion, as probable cause is required for warrants and as a condition of some of the exceptions to the warrant requirement.


A private person acting on her own behalf does not implicate the Fourth Amendment. Thus, the action of a private person searching through the personal belongings of somebody else, finding something illegal, and turning it over to the police is not a search under the Fourth Amendment. Similarly, a private person holding somebody against her will is not a seizure under the Fourth Amendment.

The definition of what constitutes a search or seizure has transitioned over the past few decades. Thus, it is important to go through a brief overview of how the Supreme Court has defined a search or seizure and its evolution over time.

In 1928, in Olmstead v. United States, 277 U.S. 438, 466 (1928), the Court applied a very narrow definition of the term “search” when a majority allowed the government to use evidence from a police tap of a private phone line without a warrant. The Court ruled that a search or seizure implicated the Fourth Amendment only when the government intruded upon an area that was protected by the Constitution and the intrusion involved a physical invasion or trespass that was constitutionally impermissible. Over a vigorous dissent, the Court expressly declined to protect intercepted phone conversations by the government by making them inadmissible.

In 1967, however, the Court overruled Olmstead in Katz v. United States, 389 U.S. 347, 352-53 (1967). Katz also dealt with a Fourth Amendment challenge to police tapping phone lines without a warrant. This time, it was a public phone booth that the defendant used. The Katz Court overruled Olmstead, ruling that the evidence stemming from the illegal recording was inadmissible. Still, the majority opinion written by Justice Stewart provided little guidance for courts to navigate Fourth Amendment cases. It was Justice Harlan’s concurrence that has served as the model definition for courts for more than 50 years. Justice Harlan’s concurrence provided that the question depended on: (1) Did the person have an actual expectation of privacy in the activity; and (2) Was that expectation one that society would recognize as reasonable? This test is known as the “reasonable expectation of privacy” test.

There are many cases in which a defendant may have had a subjective expectation of privacy, but it was not an expectation that society would recognize as reasonable. Some examples of cases where there is no reasonable expectation of privacy include aerial surveillance by police, since anyone can look down from an airplane; searching garbage left out on the curb, since anyone or anything can rummage through it; and police using registers to track phone numbers that are dialed, since numbers are willingly disclosed to the phone company, who is a third-party.


1 Thomas K. Clancy, The Framers’’ Intent: John Adams, His Era, and the Fourth Amendment, 86 Ind. L.J. 979, 990 (2011).

Author Biography:

Mary Katherine Mayer, ACP, is an Advanced Certified Paralegal in Trial Practice and Criminal Litigation. She is a paralegal with the Yavapai County Public Defender’s Office in Arizona. Mary is a member of the Arizona Paralegal Association (APA), the NALA Liaison for the APA, a member of NALA, and a member of NALA’s Professional Development Committee. Mary has written articles that have been published in several paralegal resources. When she is not working or writing, Mary enjoys spending time with her husband and son, cooking, and watching sports.