Once the Fourth Amendment applies to a particular search or seizure, the next question is under what circumstances a warrant is required to be issued. The U.S. Supreme Court has ruled that the U.S. Constitution expresses a preference for searches, seizures, and arrests conducted pursuant to a lawfully executed warrant.

A warrant is a written order signed by a court authorizing a law-enforcement officer to conduct a search, seizure, or arrest. Searches, seizures, and arrests performed without a valid warrant are deemed presumptively invalid, and any evidence seized without a warrant will be suppressed unless a court finds that the search was reasonable under the circumstances.

Read on to find out about the Fourth Amendment warrant requirement and how it could apply to you.

Requirements for a Valid Search Warrant

An application for a warrant must be supported by a sworn, detailed statement made by a law enforcement officer appearing before a neutral judge or magistrate. The U.S. Supreme Court has said that probable cause exists when the facts and circumstances within the police officer's knowledge provide a reasonably trustworthy basis for a person of reasonable caution to believe that a criminal offense has been committed or is about to take place (see Carroll v. United States).

Establishing Probable Cause

Probable cause can be established by out-of-court statements made by reliable police informants, even though those statements cannot be tested by the magistrate. However, probable cause will not lie where the only evidence of criminal activity is an officer's affirmation of suspicion or belief (see Aguilar v. Texas). On the other hand, an officer's subjective reason for making an arrest doesn't need to be the same criminal offense for which the facts indicate. (Devenpeck v. Alford).

An Officer's Oath

Probable cause will not lie unless the facts supporting the warrant are sworn by the officer as true to the best of their knowledge. The officer's oath can be written or oral, but the officer must typically swear that no knowing or intentionally false statement has been submitted in support of the warrant and that no statement has been made in reckless disregard of the truth. It's important to note, however, that inaccuracies due to an officer's negligence or innocent omission won't typically jeopardize a warrant's validity.

Details in a Warrant Application

In addition to the probable cause requirement, the Fourth Amendment warrant requirement also necessitates that a warrant "particularly" describe the person or place to be searched or seized. In other words, warrants must provide enough detail so that an officer can ascertain with reasonable effort the persons and places identified in the warrant.

For most residences a street address usually satisfies the particularity requirement, unless the warrant designates an apartment complex, hotel, or other multiple-unit building, in which case the warrant must describe the specific sub-unit to be searched. Warrants must describe individuals with sufficient particularity so that a person of average intelligence can distinguish them from others in the general population.

Neutral and Detached Magistrate

The magistrate before whom an officer applies for a warrant must be neutral and detached. This qualification means that the magistrate must be impartial and not a member of the "competitive enterprise" of law enforcement (see California v. Acevedo). Thus, police officers, prosecutors, and attorney generals are disqualified from becoming a magistrate.

States vary as to the requirements that candidates must possess before they will be considered qualified for the job of magistrate. Some states require that magistrates have an attorney's license, while others require only that their magistrates be literate.

Learn More About Fourth Amendment Warrant Requirements: Talk to an Attorney Today

Where a warrant is used, it must be lawfully obtained and executed. Any defect in this process could result in the removal of harmful evidence in your case. A skilled lawyer knows what to look for when it comes to warrants and can help you mount a strong defense. Get in touch with a criminal defense attorney in your area who can help you understand any issues related to the warrant requirement.