Fourth Amendment

Arrest

An arrest occurs when the police take a person into custody against her will for purposes of criminal prosecution or interrogation. An arrest must be based on probable cause.

Hot Pursuit Exception

Police officers in hot pursuit of a fleeing felon may make a warrantless search and seizure.

Exigent Circumstances

Police officers may enter a home without a warrant to prevent the destruction of evidence, even if the exigency arose because police officers knocked on the door and asked for entry, as long as the officers have reason to believe that evidence is being destroyed and the officers did not create the exigency through an actual or threatened Fourth Amendment violation.

Seizure

The exercise of control by the government over a person or thing.

Search Incident to a Lawful Arrest

The police may conduct a warrantless search incident to an arrest as long as it was made on probable cause.

Deadly Force

There is a Fourth Amendment seizure when a police officer uses deadly force to apprehend a suspect. An officer may not use deadly force unless it is reasonable to do so under the circumstances.

Open Fields Doctrine

Under the open fields doctrine, areas outside the curtilage are subject to police entry and search. Further, the Fourth Amendment does not prohibit the warrantless search and seizure of garbage left for collection outside the curtilage of a home.

Reasonableness

What is reasonable under the Fourth Amendment depends on the circumstances.

Seizure of Unspecified Property

When executing a warrant, the police generally may seize any contraband or fruits or instrumentalities of crime that they discovery, whether or not specified in the warrant.

Warrant Unsupported by Probable Cause

A finding that the warrant was invalid because it was not supported by probable cause will not entitle a defendant to exclude the evidence obtained under the warrant. Evidence obtained by police in reasonable reliance on a facially valid warrant may be used by the prosecution, despite an ultimate finding that the warrant was not supported by probable cause.

Search

A governmental intrusion into an area where a person has a reasonable and justifiable expectation of privacy.

Things Held Out to Public

A person does not have a reasonable expectation of privacy in objects held out to the public, such as the sound of one's voice, one's handwriting, paint on the outside of the car, the smell of one's luggage or car, account records held by a bank, or magazines offered for sale.

Reasonable Expectation of Privacy

A person has a reasonable expectation of privacy at any time: (1) she owned or had a right to possession of the place searched; (2) the place searched was in fact her home, whether or not she owned or had a right to possession of it; or (3) she was an overnight guest of the owner of the place searched.

Police Officer's Mistake of Law

A police officer's mistake of law that gives rise to reasonable suspicious does not invalidate a seizure as long as the mistake was reasonable.

Search of Persons at Premises of Warrant Location

A search warrant does not authorize the police to search persons found on the premises who are not named in the warrant. However, a warrant to search for contraband simplicity carries with it the limited authority to detain occupants of the premises while the search is being conducted.

Seizure of the Person

A seizure occurs only when, under the totality of the circumstances, a reasonable person would feel that he was not free to decline the officer's requests or otherwise terminate the encounter. Police pursuit of a suspect is not a seizure in and of itself. The Fourth Amendment requires a physical application of force by the officer or a submission to the officer's show of force. It is not enough that the officer merely ordered the person to stop.

Arrests in Homes of Third Parties

Absent exigent circumstances, the police executing an arrest warrant may not search for the subject of the warrant in the home of a this party without first obtaining a separate search warrant for the home. If the police do execute an arrest warrant at the home of a third party without obtaining a search warrant for the home, the arrest is still valid, but evidence of any crime found in the home cannot be used against the owner of the home since it is the fruit of an unconstitutional search.

Search of Automobile Incident to a Lawful Arrest

After arrest the occupant of an automobile, the police may search the interior of the auto incident to the arrest if at the time of the search: (1) the arrestee is unsecured and still may gain access to the interior of the vehicle; or (2) the police reasonably believe that evidence of the offense for which the person was arrested may be found in the vehicle.

Dog Sniffs at Entry to Home

Although the entry to a home is within the curtilage proved by the Fourth Amendment, a police officer may approach a home in hopes of speaking to its occupants. However, the scope of the license is limited. Police officers may not exceed the license by having a drug dog sniff around the entry or other area within the curtilage. Such a physical intrusion into a constitutionally protected area constitutes a search within the meaning of the Fourth Amendment and requires a valid warrant or warrant exception.

Effect of Invalid Arrest

An unlawful arrest, by itself, has no impact on subsequent criminal prosecution. Thus, if the police improperly arrest a person, they may detain him if they have probable cause to do so, and the invalid arrest is not a defense to the offense charged.

Dog Sniffs at Traffic Stops

As long as the police officers have lawfully stopped a car and do not extend the stop beyond the time necessary to issue a ticket and conduct ordinary inquiries incident to such a stop, a dog sniff of the car does not implicate the Fourth Amendment.

Automobile Stops: Pretextual Stops

If an officer has probable cause to believe that a traffic law has been violated, the officer may stop the suspect's automobile, even if the officer's ulterior motive is to investigate a crime for which the officer lacks sufficient cause to make a stop.

Wiretapping

For a valid warrant authorizing a wiretap to be issued, the following requirements must be met: (1) a showing of probable cause to believe that a specific crime has been or is being committed must be made; (2) the suspected persons whose conversations are to be overheard must be named; (3) the warrant must describe with particularity the conversations that can be overheard; (4) the wiretap must be limited to a short period of time; (5) provisions must be made for the termination of the wiretap when the desired information has been obtained; and (6) a return must be made to the court, showing what conversations have been intercepted.

Automobile Exception to Warrant Requirement: Scope of Search

If the police have full probable cause to search a vehicle, they can search the entire vehicle, including the trunk and all containers within the vehicle, that might contain the object for which they are searching. The search is not limited to the driver's belongings and may extend to packages belonging to passengers.

Automobile Exception to Warrant Requirement

If the police have probable cause to believe that a vehicle as an automobile contains contraband, fruits, instrumentalities, or evidence of a crime, they may search the vehicle without a warrant.

Arrest in a Public Place

Police generally do not need to obtain a warrant before arresting a person in a public place, even if they have time to get a warrant. A police officer may arrest a persons without a warrant when she has probable cause to believe that a felony has been committed and that the person before her committed it. An officer may make a warrantless arrest for a misdemeanor committed in her presence.

Stop and Frisk

Police have the authority to briefly detain a person for investigative purposes even if they lack probable cause to arrest. To make such a stop, police must have a reasonable suspicion supported by articulable facts of criminal activity or involvement in a completed crime. If the police also have reasonable suspicion to believe that the detainee is armed and dangerous, they may also conduct a frisk to ensure that the detainee has no weapons.

Evanescent Evidence

Police officers may seize, without a warrant, evidence likely to disappear before a warrant can be obtained.

Probable Cause for Arrest

Probable cause to arrest is present when, at the time of the arrest, the officer has within her knowledge reasonably trustworthy facts and circumstances sufficient to warrant a reasonably prudent person to believe that the suspect has committed or is committing a crime for which arrest is authorized by law.

Automobile Stops: Scope

Provided that a police officer has lawfully stopped a vehicle, in the interest of officer safety, the officer may order the occupants to get out. If the officer reasonable believes that the detainee is armed and dangerous, she may conduct a frisk of the detainee. She may also search the passenger compartment of the vehicle to look for weapons, even after the driver and other occupants have been ordered out of the vehicle.

Fourth Amendment

Provides that people should be free in their persons from unreasonable searches and seizures.

Reasonable Suspicion

Requires something more than a vague suspicion, but full probable cause is not required.

Automobile Stops

Stopping a car is a seizure for Fourth Amendment purposes. Police officers may not stop a car unless they have at least reasonable suspicion to believe that a law has been violated. An automobile stop constitutes a seizure not only of the driver, but also the passengers.

Search Incident to Incarceration or Impoundment

The police may search an arrestee's personal belongings before incarcerating him after a valid arrest. Similarly, the police may search an entire vehicle--including closed containers--that has been impounded.

Inventory Searches

The police may search an arrestee's personal belongings in order to inventory them before incarcerating the arrestee. Similarly, the police may search an entire vehicle--including closed containers--that has been impeded, as long as the search is part of an established department routine.

Consent

The police may conduct a valid warrantless search if they have voluntary consent to do so. Any person with an apparent equal right to use or occupy the property may consent to a search, and any evidence found may be used against the other owners. The search is valid even if it turns out that the person consenting to the search did not actually have such a right, so long as the police reasonably believed that the person had authority to consent. However, the police may not act on consent if a co-occupant is present and objects to the search and the search is target against the co-occupant.

Plain View Doctrine

The police may make a warrantless seizure when they: (1) are legitimately on the premises; (2) discover evidence, fruits, or instrumentalities of crime, or contraband; (3) see such evidence in plain view; and (4) have probable cause to believe (i.e., it is immediately apparent) that the item is evidence, contraband, or a fruit or instrumentality of a crime.

Fly-Overs

The police may, within the Fourth Amendment, fly over a field or yard to observe with the naked eye things therein.

Home Arrests

The police must have an arrest warrant, or be acting on a valid search warrant, to effect a nonemergency arrest of an individual in her home.

Stop and Frisk: Scope

The scope of the frisk is generally limited to a pat-down of the outer clothing for concealed instruments of assault.

Warrant Requirements

To be valid, a warrant must: (1) be issued by a neutral and detached magistrate; (2) be based on probable cause established from facts submitted to the magistrate by a government agent upon oath or affirmation; and (3) particularly describe the place to be searched and the items to be seized.