Fourth Amendment Flashcards
What is the Fourth Amendment?
The Fourth Amendment of the U.S. Constitution protects people from unreasonable searches and seizures by the government. It ensures that searches, arrests, and seizures of evidence must be conducted reasonably, usually requiring a warrant based on probable cause.
When Does the Fourth Amendment Apply?
The Fourth Amendment applies ONLY to government action. This means:
* Police officers, FBI agents, and other government officials must comply.
* Private individuals acting on their own are not bound by the Fourth Amendment.
* However, if a private person acts at the direction of law enforcement, the Fourth Amendment applies.
Example of when the Fouth Amendment Apply
Example:
🔹 A store security guard searches a customer’s bag. Not a Fourth Amendment issue—the security guard is not a government actor.
🔹 A police officer orders a store security guard to search the customer’s bag. Fourth Amendment applies—the guard is acting under government direction.
Fourth Amendment Re Searches and Seizures
What is a “Search”?
The Fourth Amendment regulates searches and seizures.
A search occurs when the government intrudes upon a person’s reasonable expectation of privacy.
The Supreme Court uses a two-prong test from Katz v. United States (1967) to determine if a search occurred:
1. Did the person have a subjective expectation of privacy?
o Did they act in a way that suggests they expected privacy?
2. Was that expectation objectively reasonable?
o Would society recognize the expectation as reasonable?
is the following a Search
Police attach a GPS tracker to a car without a warrant
Yes: ✅ Search: (United States v. Jones, 2012).
is the following a Search
Police use a thermal imaging device to scan a house for heat
(marijuana grow operation)
Yes: ✅ Search: (Kyllo v. United States, 2001).
Fourth Amendment Re Seizure
What is a “Seizure”?
A seizure occurs when the government:
1. Takes control of a person or property.
2. Restricts a person’s freedom of movement.
Is the following the a search
Police observe a suspect’s backyard from a helicopter
❌ Not a Search: (Florida v. Riley, 1989).
Is the following the a search
A police dog sniffs luggage at an airport
❌ Not a Search: (United States v. Place, 1983).
Is this following a Seizure
An arrest or when police stop a person from leaving.
I
✅ Seizure of a Person
Is this following a Seizure
Police take evidence, drugs, or weapons
✅ Seizure of Property
Is this following a Seizure
Police impound a vehicle connected to a crime.
✅ Seizure of a Car:
Is this following a Seizure
A police officer simply asks questions without restraining a person.
❌ Not a Seizure:
The Warrant Requirement
When is a Warrant Required?
The Fourth Amendment presumes that searches and seizures require a warrant, unless an exception applies.
For a valid warrant, police must show:
1. Probable Cause: Enough facts for a reasonable person to believe a crime has occurred.
2. Oath or Affirmation: Officers must swear their information is truthful.
3. Particularity: The warrant must describe:
o The place to be searched.
o The items or people to be seized.
Example of an Invalid Warrant:
🔹 A warrant authorizing police to search an entire apartment complex without specifying a particular unit.
(United States v. Hinton, 1955—invalid because it lacked particularity.)
Warrant Exceptions:
When Can Police Search Without a Warrant?
There are major exceptions to the warrant requirement.
- Search Incident to Arrest
- Automobile Exception
- Plain View
- Consent
- Exigent Circumstances
- Hot Pursuit
- Special Needs
There are major exceptions to the warrant requirement
Search Incident to Arrest
Police can search a person and their immediate surroundings after a lawful arrest. (Chimel v. California, 1969)
There are major exceptions to the warrant requirement.
Automobile Exception
If police have probable cause to believe a car contains evidence, they can search it without a warrant. (Carroll v. United States, 1925)
There are major exceptions to the warrant requirement.
Plain View
If an officer is lawfully present and sees contraband in plain view, they can seize it. (Horton v. California, 1990)
There are major exceptions to the warrant requirement.
Consent
If a person voluntarily consents to a search, no warrant is needed. (Schneckloth v. Bustamonte, 1973)
There are major exceptions to the warrant requirement.
Exigent Circumstances
A warrantless search is allowed if evidence is about to be destroyed or there is imminent danger. (Kentucky v. King, 2011)
There are major exceptions to the warrant requirement.
Hot Pursuit
If police are chasing a fleeing suspect, they can enter a home without a warrant. (United States v. Santana, 1976)
There are major exceptions to the warrant requirement.
Special Needs
Schools, airports, and border searches do not require a warrant. (Michigan v. Sitz, 1990)
The Exclusionary Rule
Definition
The Exclusionary Rule is a legal principle in criminal procedure that prevents evidence obtained in violation of a defendant’s constitutional rights from being used in a criminal trial. The rule is primarily based on the Fourth Amendment (which protects against unreasonable searches and seizures) but also extends to violations of the Fifth Amendment (protecting against self-incrimination) and the Sixth Amendment (right to counsel).
Purpose
The purpose of the Exclusionary Rule is deterrence—to discourage law enforcement from conducting illegal searches, seizures, and interrogations by removing any incentive to break the law.
Key Case: Mapp v. Ohio (1961)
The Supreme Court applied the Exclusionary Rule to state courts through the Fourteenth Amendment’s Due Process Clause.
Before Mapp, the rule only applied in federal courts (Weeks v. United States, 1914).
Example
A police officer illegally enters a suspect’s home without a warrant and finds drugs.
Because the search was conducted without a valid warrant or an exception to the warrant requirement, the drugs must be excluded from trial.
The prosecutor cannot use this evidence to convict the suspect.
If police violate the Fourth Amendment, the Exclusionary Rule applies:
* Illegally obtained evidence cannot be used in court. (Mapp v. Ohio, 1961).
* Any evidence derived from an illegal search is also excluded—this is called the Fruit of the Poisonous Tree Doctrine (Wong Sun v. United States, 1973).
Fruit of the Poisonous Tree” Doctrine
Definition
The “Fruit of the Poisonous Tree” Doctrine expands the Exclusionary Rule by stating that not only is illegally obtained evidence excluded, but any evidence derived from the illegal conduct is also excluded.
Purpose
If police obtain evidence by violating the Constitution, and that evidence leads them to more evidence, the additional evidence is also tainted and inadmissible. This prevents law enforcement from indirectly benefiting from unconstitutional conduct.
Key Case: Wong Sun v. United States (1973)
The Supreme Court ruled that evidence obtained as a direct result of an illegal search or interrogation is inadmissible unless an exception applies.
Example
Illegal Arrest: Police arrest a suspect without probable cause and interrogate him.
Confession & New Evidence: The suspect confesses and tells police where stolen goods are hidden.
Fruit of the Poisonous Tree: The confession and the stolen goods are inadmissible because they stemmed from an illegal arrest.
There are four major exceptions
Exceptions to the Exclusionary Rule & “Fruit of the Poisonous Tree”
There are four major exceptions where tainted evidence may still be admissible:
Independent Source Doctrine
If the evidence was obtained from an independent, lawful source, it may still be used.
Example: Police illegally search a warehouse and see stolen TVs. Later, they lawfully obtain a search warrant based on a different, independent tip. The evidence is admissible.
Inevitable Discovery Doctrine
If the prosecution can show that the evidence would have been discovered legally anyway, it can still be used.
Example: Police illegally search a field and find a body. However, a search team was already en route to search the same field. The body would have been found legally—so the evidence is admissible.
Attenuation (Purged Taint) Doctrine
If enough time has passed or there’s an intervening event between the illegal action and obtaining the evidence, the evidence may still be allowed.
Example: Police illegally arrest a suspect, but he is later released. Days later, he voluntarily confesses. Since there is a break in the chain of events, the confession may be admissible.
Good Faith Exception (U.S. v. Leon, 1984)
If officers acted in good faith and reasonably relied on a defective search warrant, the evidence may still be admissible.
Example: A judge issues a search warrant, but due to a clerical error, it has the wrong address. The police honestly believed they were at the right house. The evidence may still be admitted.
