Your phone has a warrant requirement. Consent is how people waive it.

Thursday, September 17, is Constitution Day, the anniversary of the signing in 1787, and the part of the Constitution that matters most to most people today is the one protecting the device in their pocket. Your phone holds more about you than your house does, and the law has caught up to that fact over the last decade. Police generally need a warrant to search it, Michigan's own constitution has named electronic data explicitly since 2020, and the U.S. Supreme Court extended those protections again this June. The rules are strong. What weakens them in practice is usually a single sentence at a traffic stop or an interview, and that's the part worth knowing before you need it.

Do police need a warrant to search your phone?

Generally, yes. In Riley v California in 2014, the U.S. Supreme Court held that police generally may not search the digital information on a cell phone seized from someone who's been arrested without a warrant, and summed up its answer in three words: get a warrant. The Court recognized that a phone holds a person's messages, photos, location history, and finances, which is far more than anything they could carry in a pocket before smartphones existed.

That doesn't mean police can't take the phone. Michigan courts have held that officers with probable cause may seize a phone while they apply for a warrant if there's a real concern that evidence could be deleted, as long as the seizure doesn't last longer than reasonably necessary. Even answering a ringing phone that belongs to someone under arrest has been held to be a search. Taking the phone and looking through it are two different steps, and the second one usually needs a judge.

What does Michigan's constitution add?

Explicit protection for electronic data. In November 2020, Michigan voters approved Proposal 2, which amended article 1, section 11 of the state constitution to say that the person, houses, papers, possessions, electronic data, and electronic communications of every person shall be secure from unreasonable searches and seizures. It also says no warrant can issue to access electronic data or communications without describing them and without probable cause supported by oath or affirmation.

That language matters in how warrants are written. In People v Carson in 2025, the Michigan Supreme Court held that a warrant allowing police to search any and all data on a phone wasn't particular enough. A warrant has to say what police are looking for and where on the device they can look, and a warrant that reads like a blank check can be challenged, which can affect what evidence is allowed at trial.

What about location data from your phone company or Google?

That needs a warrant too. In Carpenter v United States in 2018, the Supreme Court held that obtaining seven days of historical cell site location records from a phone company is a search, and that a court order based on less than probable cause wasn't enough. This past June, in Chatrie v United States, the Court held that police conducted a Fourth Amendment search when they acquired a person's location data from Google through a geofence warrant, because people have a reasonable expectation of privacy in their phone's location information, even over a two hour window.

The Court sent Chatrie back to the lower courts to decide whether that particular warrant was specific enough, so the details of how geofence warrants must be written are still developing. What's settled is that location history is protected, and police can't simply ask a tech company for it without going through a judge.

What are the exceptions to the warrant requirement?

The main ones are consent and genuine emergencies. Consent searches are valid when consent is voluntary, unequivocal, specific, and freely given, judged on all the circumstances, and the prosecution has to prove it. Consent can be limited to part of the phone, and it can be revoked. But police can ask for consent without telling you that you're free to say no, as long as a reasonable person would understand they could refuse.

Exigent circumstances, such as an immediate threat to someone's safety, can also justify a warrantless search of a particular phone, though Michigan courts have been clear that having a phone isn't an emergency by itself. Consent is the exception people hand over themselves, often by unlocking the phone when an officer asks to see a text or a photo. Our piece on what to do if police want to question you covers how to decline politely.

What about the airport?

Different rules apply at the border, and an international airport like Detroit Metro counts. U.S. Customs and Border Protection can conduct a basic manual review of a phone without a warrant, and an advanced search that connects equipment to copy or analyze the device requires reasonable suspicion or a national security concern plus a supervisor's approval. Travelers who won't unlock a device can have it detained, and noncitizens can face exclusion.

For anyone traveling internationally with a pending case or sensitive information on a phone, that's worth planning around. The Sixth Circuit, which covers Michigan, has treated an international airport as the functional equivalent of the border for these searches.

What should you do if police want your phone?

Stay calm, don't physically resist if they take it, and say clearly that you don't consent to a search. Don't unlock it, don't give the passcode, and don't offer to show them something on it, because that can turn into consent for more than you intended. Ask whether you're free to leave, and if you're under arrest, ask for a lawyer and stop talking.

If your phone has already been searched, the legality of that search can matter a great deal, because evidence from an unlawful search can sometimes be suppressed. Our criminal defense team reviews warrants, consent, and seizure timelines in cases across Wayne County, including the 19th District Court in Dearborn and the 27th District Court in Wyandotte. The Constitution gives your phone a warrant requirement, and most of the time the only person who can waive it is you.

Quick answers

Do I have to unlock my phone for police in Michigan?

You can decline to consent to a search and decline to unlock your phone. Police may still seize it while they seek a warrant if they have probable cause, and a judge may later authorize a search.

Can police look at my phone during a traffic stop?

Not without a warrant, valid consent, or a genuine emergency. Handing the phone over or unlocking it to show an officer something can be treated as consent, so it's safer to decline politely.

When did Michigan add electronic data to its constitution?

Michigan voters approved Proposal 2 in November 2020, which amended article 1, section 11 of the state constitution to protect electronic data and electronic communications from unreasonable searches and seizures.

Related reading

• What to Do If Police Want to Question You
• Who Can Search a Dorm Room in Michigan?
• Your First Court Appearance in Michigan
• Criminal Defense at D.C. Law