Fourth Amendment and cases things to knowFourth Amendment by John Bandler

by John Bandler

Fourth Amendment Q&A

  • What is the highest law in the U.S. regarding government searches and seizures?
    • The Fourth Amendment of the U.S. Constitution
  • What does the Fourth Amendment protect against?
    • The Fourth Amendment is a limit on the powers of government to search and seize. It protects against unreasonable search or seizure by the government.
  • If a judge decides police obtained evidence unlawfully, what might the judge do?
    • Suppress (exclude) the evidence pursuant to the exclusionary rule and the Fourth Amendment.
  • What document contains the fundamental principles underlying all U.S. laws?
    • U.S. Constitution
  • Why are case decisions important?
    • They establish law, precedent (stare decisis)
  • What concept describes the weight given to a prior decision by a court?
    • Legal precedent (stare decisis, authority)
  • The Fourth Amendment was ratified in 1791, thus is couldn't possibly be applied to cyber and digital evidence. True/False
    • False

The Fourth Amendment

Here's the Fourth Amendment (I added the line breaks to separate each phrase).

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.

Interesting 4th Amendment facts and conclusions by John

  • Ratified 1791
  • Word count: 54
  • Words unchanged since 1791 (232 years)
  • Toothless for almost 125 years (until Weeks in 1914) (Weeks gave it some Weak Teeth)
  • Weak teeth for almost 50 more years (until Mapp in 1961)
  • Number of words written since 1791 about what these 54 words mean?  Millions and probably billions!
  • Meaning and interpretation have evolved!
    • Proof that "originalism", "textualism", and "founders' intent" are legal concepts for Constitutional law that should be taken with a grain of salt.

Fourth Amendment Chronology and Case Progression

An evolution of law and interpretation. Initially there were no consequences for violations of the 4th Amendment, then applied only to federal government, then applicable also to state and local governments

Fourth Amendment ratified in 1791

Weeks v. United States, 232 U.S. 383 (1914)

Warrantless seizure by federal law enforcement from a private residence violates the 4th Amendment. Illegally seized evidence must be excluded (suppressed).

Burdeau v. McDowell, 256 U.S. 465 (1921)

Searches by private parties, even illegal searches, do not implicate the 4th Amendment, and suppression is not a remedy.

Gambino v. United States, 275 U.S. 310 (1927)

Searches by local or state law enforcement (in 1927) don't implicate the 4th Amendment unless it is on behalf of the federal government (silver platter).

Mapp v. Ohio, 367 U.S. 643 (1961)

4th Amendment applies to states (not just the feds) via Due Process clause of the Fourteenth Amendment. Illegal searches by local law enforcement do implicate the 4th Amendment, and suppression (exclusion) is a remedy.

Katz v. United States, 389 U.S. 347 (1967).

4th Amend applies to conversations too. Concept of reasonable expectation of privacy (REP) from Government

Terry v. Ohio, 392 U.S. 1 (1968)

Police may temporarily detain (stop) and possibly pat down frisk based upon reasonable suspicion (which is less than probable cause).  “Stop and frisk” is Constitutionally permissible.

People v. Zelinksy, 24 Cal 3d 357 (Cal Sup Ct 1979)

Under California law, an illegal private search by a private entity, used in a criminal case, could be subject to suppression under the California Constitution.

Minnesota v. Buswell, 449 N.W.2d 471 (Minn. App. 1989) Ch 8 p.459.

Under Minnesota law, it is not enough just to say it was a private search to evade the 4th Amendment. The court must analyze whether there was government involvement.

Now let's get digital

This is the time to play this song via YouTube.

United States v. Jones, 565 U.S. 400 (2012). GPS tracking using a device is a search, requiring a search warrant supported by probable cause.

Riley v. California, 573 U.S. 373 (2014) Law enforcement needs a search warrant to search a defendant's cell phone. The warrant exception for search incident to lawful arrest might cover pockets and beyond, but definitely does not cover searching contents of a cell phone.

Carpenter v. United States 585 U.S. ___ (2018). Law enforcement's obtaining of third-party location data requires a search warrant and a showing of probable cause.

ECPA, Electronic Communications Privacy Act

A statute that lays out the procedure for law enforcement to obtain electronic evidence, consistent with the Fourth Amendment. (It also prohibits certain online conduct, but that's a different matter)


These are short Q&As and summaries cannot be expected to capture all nuances of all terms or decisions.

Purpose of this page

This page is a study aid for my students, and a place for me to draw quiz and assignment questions from. The goal is for students to learn important concepts, especially foundational concepts that provide footholds for learning more complex concepts.


This page is hosted at, copyright John Bandler, all rights reserved.

Posted 5/3/2023 based on years of teaching. Updated 11/14/2023