Constitutional protection of accused persons - Arrest, searc...

Learning Outcomes

This article explains constitutional protection of accused persons in the context of arrest, search, and seizure, including:

• Determining when the Fourth Amendment is triggered by government action and when private conduct falls outside its scope.
• Distinguishing arrests, investigatory (Terry) stops, traffic stops, and consensual encounters based on the level of suspicion and the degree of restraint.
• Identifying when probable cause, reasonable suspicion, or no suspicion is required, and applying those standards to common fact patterns.
• Evaluating when officers must obtain a warrant, what a valid warrant requires, and when recognized exceptions permit warrantless searches or seizures.
• Analyzing the proper scope of searches incident to arrest, automobile searches, protective sweeps, consent searches, plain-view seizures, and exigent-circumstances entries.
• Applying the exclusionary rule, “fruit of the poisonous tree,” and the good‑faith exception to determine whether evidence will be suppressed or admitted.
• Spotting frequent MBE traps involving standing, third-party consent, home entries to arrest, pretextual traffic stops, knock‑and‑announce violations, and border or administrative searches.
• Organizing a step‑by‑step approach to Fourth Amendment questions to quickly eliminate distractor answers and select the best response under exam time pressure.

MBE Syllabus

For the MBE, you are required to understand constitutional rules governing arrests, searches, and seizures, with a focus on the following syllabus points:

• The scope and application of the Fourth Amendment to government action.
• Requirements for valid arrests, including probable cause and warrant rules.
• Distinctions between arrests, investigatory stops (Terry stops), and consensual encounters.
• The warrant requirement for searches and seizures, and recognized exceptions.
• The exclusionary rule, “fruit of the poisonous tree,” and their limitations.
• Standards for probable cause and reasonable suspicion.
• Rules for consent, plain view, automobile searches, and exigent circumstances.
• The effect of improper search or seizure on admissibility of evidence in different proceedings.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which of the following is required for a valid arrest under the Fourth Amendment?
   1. A warrant in all cases
   2. Probable cause that a crime has been committed
   3. Reasonable suspicion of criminal activity
   4. Consent of the accused
2. Evidence obtained from a warrantless search of a home will generally be excluded unless:
   1. The search was incident to a lawful arrest
   2. The officer had reasonable suspicion
   3. The officer was acting under a state statute
   4. The search was conducted by a private citizen
3. The exclusionary rule does NOT apply in which of the following situations?
   1. Grand jury proceedings
   2. Criminal trials
   3. Motions to suppress evidence
   4. Police conduct that shocks the conscience

Introduction

The U.S. Constitution provides significant protection to individuals accused of crimes, especially during arrest, search, and seizure. The Fourth Amendment is the primary source of these protections, limiting government action and setting standards for law enforcement conduct. For MBE purposes, you must know not only the black-letter rules, but also when the Fourth Amendment is triggered, who can invoke it, and what happens when it is violated.

Key Term: Fourth Amendment
The constitutional provision protecting individuals against unreasonable searches and seizures by the government. It generally requires probable cause and, for most home searches, a warrant issued by a neutral magistrate.

Fourth Amendment: Government Action and Standing

The Fourth Amendment restricts government conduct, not purely private conduct. This is a recurring MBE issue.

Key Term: Government Action
Action by federal, state, or local officials, or by private individuals who are effectively acting as agents or instruments of the government.

Key Term: State Actor
A government official or a private person so closely directed or controlled by the government that their conduct is treated as governmental for constitutional purposes.

Security guards, store detectives, or neighbors acting entirely on their own usually are not state actors. But a private person can become a state actor if the police initiate, direct, or significantly involve themselves in the search.

Key Term: Standing
The requirement that a defendant personally have a reasonable expectation of privacy in the place searched or item seized in order to challenge a search or seizure under the Fourth Amendment.

You cannot vicariously assert someone else’s Fourth Amendment rights. A defendant generally has standing when:

• They own or possess the place searched.
• The place is their home (even if rented or not formally owned).
• They are an overnight guest in the premises.

A mere visitor or former co-occupant who has moved out usually lacks standing to challenge a search of the premises.

What Counts as a Search or Seizure

A search occurs when the government intrudes on an area or item in which a person has a reasonable expectation of privacy, or when there is a physical intrusion into a constitutionally protected area to obtain information.

Key Term: Search
Government intrusion into an area where a person has a reasonable expectation of privacy, or physical trespass into a protected area (e.g., home, effects) to gather information.

Common situations where there is no reasonable expectation of privacy (and therefore no Fourth Amendment “search”) include:

• What can be seen from public vantage points (e.g., aerial observation of a yard).
• Trash left at the curb for collection.
• Bank records, phone numbers dialed, and other information voluntarily given to third parties.
• Open fields outside the home’s curtilage.

A seizure of a person occurs when, under the totality of circumstances, a reasonable person would not feel free to leave or terminate the encounter.

Key Term: Seizure
Government interference with a person’s freedom of movement or possessory interests in property, such that a reasonable person would not feel free to leave, or where property is meaningfully interfered with.

Simply approaching someone and asking questions is not a seizure if the person remains free to walk away.

Probable Cause, Reasonable Suspicion, and Levels of Encounters

Fourth Amendment analysis often turns on the level of suspicion the officer has and the degree of intrusion on the individual.

Key Term: Probable Cause
A fair probability, based on objective facts, that a crime has been committed and that the person to be arrested committed it, or that specific evidence will be found in the place to be searched.

Key Term: Reasonable Suspicion
A specific and articulable, objective basis for suspecting criminal activity, based on the totality of the circumstances. It is less than probable cause but more than a mere hunch.

Police–citizen interactions fall into three main categories:

• Consensual encounter: no suspicion required; the person is free to leave.
• Investigatory stop (Terry stop): requires reasonable suspicion.
• Arrest: requires probable cause.

Key Term: Terry Stop
A brief detention based on reasonable suspicion that criminal activity is afoot; may be accompanied by a limited frisk for weapons if the officer reasonably believes the suspect is armed and dangerous.

Arrests: Probable Cause and Warrants

An arrest occurs when law enforcement takes a person into custody for prosecution or interrogation. The Fourth Amendment requires that arrests be based on probable cause—a reasonable belief that a crime has been committed and that the person arrested committed it.

A warrant is not required for most arrests in public places if officers have probable cause. However:

• To enter the suspect’s own home to arrest them, officers ordinarily need:
  • An arrest warrant, and
  • Reason to believe the suspect is inside.
• To enter a third party’s home looking for the suspect, officers generally need a search warrant (or consent or exigent circumstances).

Deadly force to make an arrest is a seizure and is reasonable only if the suspect poses a significant threat of death or serious physical injury to the officer or others.

Investigatory Stops: Reasonable Suspicion

Brief stops (Terry stops) are permitted on reasonable suspicion that criminal activity is afoot. Reasonable suspicion can be based on the officer’s observations, tips, or the suspect’s behavior, viewed under the totality of circumstances.

Officers may also conduct a limited frisk for weapons if they reasonably believe the person is armed and dangerous. The frisk is limited to a pat-down of outer clothing to feel for weapons; evidence felt as plainly contraband may also be seized.

Traffic stops are Terry-type seizures. Key MBE points:

• A pretextual stop (e.g., stopping for a minor traffic violation while hoping to find drugs) is valid if the officer has objective probable cause for the traffic violation.
• During a lawful traffic stop, officers may order both driver and passengers out of the vehicle and may frisk them (and, if warranted, the passenger compartment) for weapons.

Searches and Seizures: Warrant Requirement and Search Warrants

A warrant is required for most searches and many home entries. The warrant must:

• Be issued by a neutral and detached magistrate.
• Be supported by probable cause.
• Describe with particularity the place to be searched and items to be seized.

Officers must limit their search to areas where the described items could reasonably be found, but may seize any contraband in plain view while lawfully executing the warrant.

Execution of Warrants

Typical exam-tested points:

• Police must generally knock and announce their presence and purpose before forcibly entering, unless they reasonably suspect doing so would be dangerous, futile, or allow destruction of evidence.
• A violation of the knock-and-announce rule does not lead to suppression of evidence on the MBE.
• A warrant to search premises does not automatically authorize search of all persons found inside; officers need individualized probable cause for each person, absent some exception (e.g., search incident to arrest).

Exceptions to the Warrant Requirement

While warrants are strongly favored, a number of well-defined exceptions allow warrantless searches when officers have the required level of suspicion.

Key Term: Search Incident to Lawful Arrest
A warrantless search of an arrestee and the area within their immediate control, justified by officer safety and preservation of evidence, when the arrest itself is lawful.

Key Term: Automobile Exception
The exception allowing warrantless search of a vehicle (and containers within it) if police have probable cause to believe it contains contraband or evidence of a crime.

Key Term: Plain View Doctrine
The rule allowing officers lawfully present in an area to seize items that are immediately apparent as contraband or evidence without a warrant.

Key Term: Exigent Circumstances
Situations such as hot pursuit, imminent destruction of evidence, or emergency aid where the need for swift action makes it reasonable to proceed without a warrant.

Common warrant exceptions tested on the MBE include:

• Search incident to lawful arrest

  • Person: full search of the arrestee’s person and containers on them.
  • Immediate area: areas within the arrestee’s immediate grabbing distance.
  • Vehicles: after a recent occupant is arrested, police may search the passenger compartment only if:
    • The arrestee is unsecured and could still access the vehicle, or
    • It is reasonable to believe evidence of the offense of arrest may be found in the vehicle.

• Automobile exception

  • If police have probable cause that a vehicle contains contraband or evidence, they may search the entire vehicle, including trunk and any containers that might hold the object.
  • Probable cause can arise after a valid stop (e.g., strong odor of marijuana, visible contraband).
  • The search may occur roadside or later at the station.

• Consent

  • Officers may search if a person voluntarily consents.
  • Knowledge of the right to refuse is relevant but not required.
  • Consent can be given by someone with actual or apparent authority over the area.
  • If one present co-occupant consents and another physically present co-occupant expressly refuses, consent is ineffective as to areas over which the objecting occupant shares authority.

• Plain view

  • Officers must be lawfully present.
  • The incriminating nature of the item must be immediately apparent (probable cause).
  • They cannot manipulate objects or move them substantially to gain the view.

• Exigent circumstances

  • Hot pursuit of a fleeing felon.
  • Reasonable belief that evidence will be destroyed before a warrant can be obtained.
  • Emergency aid to a person inside (e.g., screams, apparent medical emergency).

• Protective sweeps and inventory searches

  • Protective sweep: during or immediately after an in-home arrest, officers may conduct a quick sweep of adjoining spaces for persons who might pose a danger, based on reasonable suspicion.
  • Inventory: after lawful impoundment of a vehicle, or booking of an arrestee, police may perform a standardized inventory of property, including closed containers.

• Administrative and border searches

  • Certain highly regulated industries and border crossings allow warrantless inspections under neutral schemes. These are tested less frequently on the MBE than the core exceptions above.

Worked Example 1.1

Police, without a warrant, enter a suspect's home after hearing screams and seeing smoke. They find illegal drugs in plain view and seize them. The suspect moves to suppress the evidence at trial. Is the evidence admissible?

Answer:
Yes. The entry was justified by exigent circumstances (a possible emergency involving screams and smoke), and the drugs were in plain view during a lawful entry. No warrant was required.

Worked Example 1.2

An officer stops a car for speeding and, during the stop, smells marijuana. The officer searches the car's trunk and finds contraband. The driver challenges the search. Was the search valid?

Answer:
Yes. The automobile exception allows a warrantless search of a vehicle if there is probable cause to believe it contains evidence of a crime. The odor of marijuana provided probable cause, and the trunk may be searched because drugs could be located there.

Worked Example 1.3

A store’s security guard, on his own initiative, tricks an employee into inviting him home so he can check the serial number on a TV he suspects is stolen. He reports the serial number to police, who then obtain a warrant and seize the TV. The employee moves to suppress.

Answer:
The motion should be denied. The security guard was not acting as a government agent; he conducted a private search. The Fourth Amendment does not apply to purely private searches, so the information he provided could properly form the basis for a warrant.

Worked Example 1.4

A defendant had been living with a business partner but moved out, leaving a bag containing cocaine and his ID in the partner’s house. Police later search the house with the partner’s consent and find the bag. The defendant moves to suppress.

Answer:
The motion should be denied. The defendant no longer lived there and had relinquished any reasonable expectation of privacy in the premises. Without standing to challenge the search of the partner’s home, he cannot invoke the Fourth Amendment.

The Exclusionary Rule

When the Fourth Amendment is violated, the usual remedy is exclusion of the resulting evidence from the prosecution’s case-in-chief.

Key Term: Exclusionary Rule
A judicially created rule that bars the prosecution from using evidence obtained in violation of the Constitution in its case-in-chief against the defendant.

Key Term: Fruit of the Poisonous Tree
Evidence that is indirectly derived from unconstitutional conduct (e.g., statements, physical evidence, or identifications obtained via an earlier illegal search or seizure).

Not only is the directly seized evidence excluded; fruit of the poisonous tree is also excluded unless an exception applies. However, the exclusionary rule has important limits.

When the Exclusionary Rule Does Not Apply

The exclusionary rule generally does not apply:

• In grand jury proceedings, civil cases, or parole revocation hearings.
• To impeach the defendant with otherwise suppressed evidence (though only certain violations allow this).
• To knock-and-announce violations during warrant execution.
• Where the defendant lacks standing to challenge the search.

The rule also does not bar evidence obtained through:

• Independent source: lawfully obtained evidence from a completely separate, independent source.
• Inevitable discovery: evidence that would inevitably have been discovered by lawful means.
• Attenuation: where the causal link between the illegality and the evidence is sufficiently remote (e.g., voluntary act by the defendant or long passage of time).

Key Term: Good-Faith Exception
An exception to the exclusionary rule that allows admission of evidence obtained by officers acting in objectively reasonable reliance on a warrant or statute later found invalid, absent certain serious defects.

Under the good‑faith exception, evidence will not be excluded if police reasonably relied on:

• A warrant later held unsupported by probable cause.
• A warrant later held technically defective in form.
• A statute or precedent later declared unconstitutional or invalid.

Good faith does not apply if:

• The warrant is so facially deficient that officers could not reasonably rely on it (e.g., lacks particularity).
• The magistrate was not neutral and detached.
• Officers knowingly or recklessly included false information in the affidavit.

Worked Example 1.5

Police obtain a warrant to search a basement for methamphetamine and related equipment. While lawfully searching the basement, they find a notebook labeled “Ledger” listing customer names and amounts owed. The warrant does not list notebooks. The defendant moves to suppress the ledger.

Answer:
The best argument for suppression is lack of particularity: the notebook was not described in the warrant. However, because the notebook was evidence closely related to drug dealing and found in a place described in the warrant where such records might reasonably be located, it falls within the scope of the warrant and is admissible.

Worked Example 1.6

Police execute a valid arrest warrant for X at X’s neighbor’s home by pushing past the neighbor without consent after seeing X inside. While inside, they observe marijuana on the neighbor’s kitchen counter and seize it. The neighbor is charged and moves to suppress, arguing plain view does not apply.

Answer:
The neighbor’s motion should be granted. The arrest warrant for X did not authorize entry into a third party’s home without consent or a search warrant. Because the officers were unlawfully inside the neighbor’s home, they were not lawfully present when they saw the marijuana, so the plain view doctrine does not apply.

Exam Warning

• The exclusionary rule does not apply to evidence offered in grand jury proceedings, civil cases, or many non-trial contexts such as parole revocation.
• A mere violation of state law or internal police policy does not automatically trigger suppression; the question is whether the U.S. Constitution was violated.

Revision Tip

Always proceed in this order for Fourth Amendment questions:

1. Identify government action and whether the defendant has standing.
2. Determine if there was a search or seizure.
3. Ask whether officers had a warrant or a recognized exception.
4. If there was a violation, analyze whether the exclusionary rule applies or an exception (good faith, independent source, inevitable discovery, attenuation) saves the evidence.

Key Point Checklist

This article has covered the following key knowledge points:

• The Fourth Amendment protects against unreasonable searches and seizures by government actors, not purely private individuals.
• A defendant must have standing—a personal reasonable expectation of privacy—to challenge a search or seizure.
• Arrests require probable cause; a warrant is generally needed to enter a suspect’s home, and a search warrant is needed to enter a third party’s home, absent consent or exigent circumstances.
• Investigatory (Terry) stops require reasonable suspicion; a frisk for weapons requires a reasonable belief the suspect is armed and dangerous.
• Searches and seizures generally require a warrant supported by probable cause and particularity, issued by a neutral and detached magistrate.
• Warrantless searches may be justified under specific exceptions, including search incident to lawful arrest, the automobile exception, consent, plain view, exigent circumstances, protective sweeps, and standardized inventory searches.
• The exclusionary rule bars evidence obtained in violation of the Fourth Amendment and its fruits from the prosecution’s case‑in‑chief, subject to key exceptions (independent source, inevitable discovery, attenuation, and good‑faith reliance).
• The exclusionary rule does not apply in grand jury proceedings, most civil cases, or to certain technical violations (e.g., knock-and-announce).
• Pretextual traffic stops are valid if there is objective probable cause for the traffic offense; officers may order occupants out and, if justified, frisk for weapons.

Key Terms and Concepts

• Fourth Amendment
• Government Action
• State Actor
• Standing
• Probable Cause
• Reasonable Suspicion
• Search
• Seizure
• Terry Stop
• Search Incident to Lawful Arrest
• Automobile Exception
• Plain View Doctrine
• Exigent Circumstances
• Exclusionary Rule
• Fruit of the Poisonous Tree
• Good-Faith Exception