Warrant Requirement

What It Is

The Fourth Amendment protects you from unreasonable searches and seizures. The core rule is simple: police generally need a warrant — a court order based on probable cause — before they can search your home, your belongings, or seize your property.

As the Supreme Court stated in Katz v. United States, 389 U.S. 347 (1967), “searches conducted outside the judicial process, without prior approval by judge or magistrate, are per se unreasonable under the Fourth Amendment — subject only to a few specifically established and well-delineated exceptions.”

What a Valid Warrant Requires

A valid warrant must have:

1. Probable cause — Facts showing it is more likely than not that evidence of a crime will be found in the place to be searched.
2. Particularity — The warrant must specifically describe the place to be searched and the items to be seized. No “general warrants” allowed.
3. Judicial approval — A neutral judge or magistrate must review and sign the warrant. Police cannot issue warrants to themselves.
4. Oath or affirmation — The officer seeking the warrant must swear to the facts under penalty of perjury.

The Home Gets the Strongest Protection

The Supreme Court has repeatedly emphasized that the home is entitled to the highest Fourth Amendment protection. Payton v. New York, 445 U.S. 573 (1980) held that police need an arrest warrant to enter a home to arrest someone, absent exigent circumstances.

In the digital age, Riley v. California, 573 U.S. 373 (2014) extended warrant protection to cell phones, and Carpenter v. United States, 585 U.S. 296 (2018) required warrants for historical cell-site location data.

Exceptions to the Warrant Requirement

The warrant requirement has well-established exceptions, including:

• Exigent circumstances — emergencies that make getting a warrant impractical
• Consent — you voluntarily agree to the search
• Search incident to arrest — officers can search you and the area within your reach when making a lawful arrest
• Plain view — officers can seize evidence in plain sight if they are lawfully in a position to see it
• Automobile exception — vehicles can be searched with probable cause but without a warrant, due to their mobility
• Terry stops — brief investigative stops and pat-downs based on reasonable suspicion

Practical Tips

• If police searched without a warrant, determine which exception (if any) they relied on. If no exception applies, the search was likely unconstitutional.
• Document everything. Write down what happened, what the officers said, and whether they showed you a warrant.
• A warrant must be specific. If police searched areas or seized items not listed in the warrant, the search may have exceeded its scope.
• You can refuse consent. Politely but clearly say “I do not consent to a search.” See consent search.

Key Takeaway

Police generally need a warrant to search you or your property. When they search without one, the burden falls on the government to prove an exception applies.