The Fourth Amendment to the United States Constitution protects people against unreasonable searches by the police. Searches can be conducted of property (e.g., a house, a desk drawer), or of people.

Generally, to conduct a search, the police must obtain a warrant from a judge or magistrate. The warrant, known as a search warrant, must specify what places are to be searched. The warrant must also specify what items related to criminal activity are expected to be found. For a judge or magistrate to issue a warrant, the judge or magistrate must find that there is probable cause to conduct the search. In addition, the search may not be conducted in a manner inconsistent with an individual’s reasonable expectation of privacy.

If the search is conducted without probable cause, or inconsistently with a person’s reasonable expectation of privacy, the search can be ruled illegal. Generally, the results of an illegal search are excluded from the evidence the prosecution can use against a criminal defendant. In other words, they can’t use the evidence in court.

What is a Reasonable Expectation of Privacy?

A person has a reasonable expectation of privacy with respect to a place to be searched, when:

  • The individual expects privacy with respect to the location to be searched; AND
  • Society recognizes this expectation of privacy as “reasonable.” 

Places where an individual generally has an expectation of privacy include the person’s home, apartment, or hotel room. These places have been traditionally considered to be “private”, or hidden from public view.

An individual generally does not have an expectation of privacy with respect to areas or places that can be lawfully and publicly accessed or viewed. 

For example, if the police presence at or on a public area is lawful, items that the police encounter may generally be searched. Such items include, for example, trash bags or other items left for garbage disposal. These items are generally regarded as “publicly accessible.” 

In addition, if the public is capable of lawfully viewing an area, the police may search that area. An example of such an area is the open fields that surround, but are not part of, a person’s home.

What Kinds of Searches Can be Conducted?

Generally, searches may be conducted of residences, automobiles, and individuals.

Searches of the home are generally permitted, but only if the police first secure a valid warrant. Once the police are in possession of a search warrant that specifically describes areas to be searched, items to be found, and where the items are expected to be found, the search can be conducted. 

An important exception to the rule requiring a warrant to search a home is known as the “exigent circumstances” exception. Under this exception, if the police are in “hot pursuit” of an individual, and there is probable cause to believe that search of a location where the hot pursuit is occurring may yield evidence (e.g., a weapon or clothes an individual is attempting to dispose of), the search may be conducted without a warrant.  

Automobiles may be searched as well. If the police have probable cause to believe that evidence of a crime is located in a vehicle, the “automobile exception” to the warrant requirement permits the police to warrantlessly search those areas of the automobile where the item may be located. 

Automobiles may also searched as an “incident to a lawful arrest”. If a person is validly arrested, the police may search the automobile following the arrest and detention of the arrested individual, if (and only if) there is reason to believe that the vehicle contains evidence of the offense of the arrest. 

Generally, a police officer who has written a citation for a minor traffic offense may not further search a vehicle that was stopped for the offense. 

Individuals may also be searched. Upon making an arrest supported by probable cause, the police may conduct a search of the person and their immediate surroundings. This warrantless search is allowed so the police can search for weapons or other items that may harm the police.

Are there Other Exceptions to the Warrant Requirement?

There are additional circumstances under which the police may conduct a search without a warrant. 

When there is probable cause to believe that an item is evidence of a crime, and the police lawfully observe the item in plain view or plain sight, the police may generally search the item. Under such circumstances, a warrant is not required.

If an individual consents to a search, neither a warrant nor probable cause are generally required. However, if an individual consents to a search, the scope of the search is limited to the extent of the consent.

What if a Search is Conducted Illegally?

Items obtained during a search that is not supported by probable cause, or that was conducted unreasonably, may be excluded; that is to say, such items may not be considered as evidence against a defendant. A defendant’s lawyer typically files what is known as a “motion to suppress” to demand that such evidence be excluded. 

Do I Need a Lawyer if I Believe an Unlawful Search Has Occurred?

If you believe that an unlawful search has occurred, you may wish to consult with a criminal defense lawyer. An experienced criminal defense lawyer near you can assess the facts and circumstances of your case, and can represent you at hearings and at trial.