Can a court force you to unlock a phone with your fingerprint? Yep

If investigators need your fingerprint to access your phone for a case, they can probably get it.

A court can order a criminal suspect to use their fingerprint to unlock a phone – and it's not a violation of their Constitutional rights.

That's what the Minnesota Supreme Court said Wednesday, in which it ruled on a question that hasn't been touched by the U.S. Supreme Court, or any other state supreme court up to this point.

The case involves Matthew Diamond, who was arrested in 2014 in connection with a burglary. Authorities got a warrant to seize and search his cellphone, and when they needed Diamond's fingerprint to unlock it, a judge ordered him to give it.

The state used texts, phone calls and cellphone ping data during the trial to make its case, and Diamond was found guilty.

But Diamond appealed.

He argued, in part, that being forced to give his fingerprints was essentially the same as making somebody testify against themselves – which they can't do. That's why the whole "plead the 5th" thing exists.

What the ruling says

The Minnesota Court of Appeals didn't see it Diamond's way in its ruling from January 2017. And neither did the state Supreme Court, which upheld the appeals court's decision.

The basic question is: If investigators used data found on Diamond's phone – only unlocked because he was ordered to use his fingerprint – as part of the case, does that amount to Diamond being forced to incriminate himself?

The answer is no, the state Supreme Court said (you can read the full opinion here).

That's because the 5th Amendment only protects a suspect from "testimonial communication," actually offering something up knowledge from their mind.

Providing a fingerprint to unlock a phone is simply presenting a physical characteristic, similar to "standing in a lineup or providing a blood, voice, or handwriting sample."

In addition, the "act of providing a fingerprint to the police was not testimonial because the act did not reveal the contents of Diamond’s mind."

So, no Constitutional violation.

What about a passcode? That's trickier

The Minnesota Supreme Court has said using your fingerprint to unlock a phone isn't forcing you to give up something you know. It's a conclusion other judges around the country have come to also, as The Atlantic wrote about.

But what about your passcode?

As the Consumerist wrote, judges in Michigan and Virginia have ruled suspects can not be required to give phone unlock codes. That's because it's forcing the suspect to communicate knowledge – which is possibly self-incriminating.

A new wrinkle is the facial recognition scanning unlock technology the iPhone X touts so much.

That seems like it would fall into the same category as providing a fingerprint. But no court has actually ruled on it.

According to a Washington Post story from September of 2017, the final answer to that simply isn't known.

“Ultimately, this is the next development in the already existing, open legal question," Susan Hennessey, managing editor of Lawfare, told the paper.

There is a way to quickly disable an iPhone's biometric unlocks. As Wired reports, iOS11 has an "SOS" mode – if someone taps the home button five times in quick succession, it will disable TouchID and/or FaceID (depending on the model) and revert back to a passcode lock screen.

Next Up

Image from iOS (101)

Charges: Driver was drunk, speeding before crash that killed 1-year-old son

A total of five children were in the back seat at the time, according to the charges.

Jeff Gladney

Vikings release Jeff Gladney following domestic violence charge

His release is effective immediately, the team said.

Screen Shot 2021-08-03 at 3.28.56 PM

Body pulled from water near Lebanon Hills Park swimming area

Surveillance footage showed a man walking towards the beach on Sunday.

fire truck

Victims of double-fatal house fire in Wadena County identified

The man and woman died in the early Sunday house fire.

Screen Shot 2021-08-03 at 7.50.23 AM

Charges: Witness thought Austin man was 'joking' before he killed woman

The criminal complaint details what may have led to the 20-year-old's death.

Melvin Carter

Minneapolis and St. Paul to require face masks in city buildings

The mayors are also urging businesses to adopt mask rules for customers.


Charges detail murder of woman by fugitive bomb-maker husband

Eric Reinbold is accused of killing his 34-year-old wife.

Jeff Gladney

Vikings' 2020 first-round pick Gladney indicted by Texas grand jury

If convicted Gladney could be sentenced up to 10 years in prison.

face mask

List of places in Minnesota now requiring or recommending face masks

Businesses and organizations are changing their policies in response to the delta variant.

Minnesota State Fair - main gate day 2021

The 2021 Minnesota State Fair: Everything you need to know

From ticket prices to new foods to health protocols, we've got you covered.

Flickr - police lights squad siren - Edward Kimmel

Suspect steals unlocked squad car, leads officers on miles-long chase

The suspect also brandished a shotgun from the stolen vehicle out the window.


You can Boomerang from inside Instagram now

Get some sweet Boomerangs in your Instagram story.

Do you know when Uber is tracking your location?

We know apps collect data about us. But how much, and how is it being used?

Samsung is 'truly sorry' for the whole exploding phone fiasco

Remember the Note7 burns and explosions? Samsung is sorry about that.

Let your Uber driver know where you are without having to awkwardly call them

No more revealing your personal phone number to a stranger.

New proposal: Internet companies should pay you if they use or sell your data

It's your data that's valuable – should you get compensated for it?

Facebook is trying to make fewer crappy links show up on your feed

You know the ones – where the page you go to is full of an absurd number of ads.

Netflix remembers every time you pause a show (and a lot of other info)

It sees you when you're binging. It knows when you hit pause.