Skip to content
Fingerprint
Naked Security Naked Security

Police try (and fail) to unlock phone with a dead man’s finger

The practice doesn't require a warrant but it left relatives feeling "disrespected and violated."

It must have seemed worth a try: within the window of time where it’s still possible to unlock a phone with a fingerprint, go to the funeral home and make use of the deceased’s finger. It’s a lot cheaper than paying some forensics outfit to crack it open, and likely quicker too. However, this most recent case was just as successful as previous attempts: as in, not at all.
According to the Tampa Bay Times, Florida police attempted to unlock the phone after they shot and killed 30-year-old Linus F. Phillip, whom they wanted to question in a drug investigation, on 23 March.
Phillip was detained at a gas station in Largo, Florida. An officer tried to search him. Phillip didn’t cooperate. Rather, he tried to drive away, which is when the officer shot him.
Lt. Randall Chaney told the Tampa Bay Times that investigators had a 48- to 72-hour window in which to unlock the phone’s fingerprint sensor. They had the phone, and once the state released the body to a funeral home, they got the chance to try out the dead man’s fingers, so that’s where they paid a visit.
It didn’t work.
That’s not surprising. Police have repeatedly tried to unlock phones with dead fingers, but if it’s ever worked, we haven’t heard about it.
It’s perhaps not surprising. We don’t know what type of phone Phillip had, but fingerprint sensors such as Apple’s Touch ID use capacitive touch, picking up on the slight electrical charge that runs through living skin in order to read a fingerprint at a sub-dermal level.
Even if the capacitance sensor was artificially triggered, Touch ID’s radio frequency only responds to living tissue.
Still and all, police have tried this before.
There are alternatives: multiple outfits that promise they can hack phones, but it doesn’t come cheap.
The most prominent name is that of Cellebrite, widely believed to be the firm that broke into the iPhone 5C belonging to dead San Bernadino terrorist and mass murderer Syed Rizwan Farook.


As The Intercept has reported, a US Drug Enforcement Administration procurement record shows that as of September 2016, Cellebrite’s premium unlocking subscription service cost $250,000 a year in the US. As of 2016, one-off hacks were selling for about $1,500 per phone.
Then too, there’s US startup GrayShift, which sells a $15,000 device called GrayKey that promises to unlock the iPhone 8 and X.
Cost isn’t the only incentive pushing police towards the use of dead people’s fingerprints. Warrants aren’t required to get a dead person’s prints, given that after death, people lose privacy interest in their own body. In other words, they have no standing in court to assert privacy rights.
The first known case of using a dead man’s fingers to try to unlock an iPhone was that of Abdul Razak Ali Artan, an 18-year-old Somali immigrant who plowed his car into a group of people on the Ohio State University campus, attacked victims with a butcher’s knife, and was shot dead by police in November 2016.
Police failed in that case: not only was Artan dead, but they were swiping his finger after the window of opportunity had closed, when the phone goes into sleep mode and requires a passcode to unlock.
Sources have told Forbes that it’s now a “relatively common” procedure to press dead people’s fingers to their phones. It’s been used in overdose cases, for example, as police have sought drug dealers.
In another case, from July 2016, police sought to make a cast from a dead man’s prints, but not from his actual fingers. They asked for 3D prints to be made from fingerprints they already had on file.
Phillip’s fiancée, Victoria Armstrong, was at the funeral home when Florida investigators swiped his fingerprints. She said she felt “disrespected and violated.”
Courts may have no problem with police swiping dead people’s fingers, but there are experts who want them to rethink the ghoulish practice. The Tampa Bay Times spoke to one, Greg Nojeim, director of the Freedom, Security and Technology Project at the Washington-base Center for Democracy and Technology, who said that the Largo detectives’ actions were “ethically unjustifiable.”

There should be some dignity in death. If I was writing the rules on this, it would be that the police would need a warrant in order to use a dead person’s finger to open up a phone, and I’d require notice to the family.

In the meantime, if you want to ensure that you can’t be compelled to use your fingerprints to unlock your phone – be you deceased or not – use a passcode instead of biometrics for authentication.
Courts have generally held that you can’t be compelled to give up your passcode because of Fifth Amendment protection against giving testimony (i.e., something you know) that could be used against you, whereas your biometrics (i.e., something you are) are pretty much up for grabs.


10 Comments

Should have pealed off a couple layers of skin, glue it to a living hand and try. but not to my hand, just a little to creepy for me.

If you can unlock iPhones (not sure if this was an iPhone, TBH) with a woodglue mould of a fingerprint that’s been breathed on to give it a suitable conductivity to work with the sensor, I’m not covninced that alive/dead is the issue here.

I was going by the article part; ‘fingerprint sensors such as Apple’s Touch ID use capacitive touch, picking up on the slight electrical charge that runs through living skin in order to read a fingerprint at a sub-dermal level.” led me to think if the dead skin was thin enough it would conduct. I see your point that if the glue part works.

IIRC, one way to make the glue print work is to breathe on it; another is to lick it. That might need a strong will to do with a corpse.

The use of dead people peoples body parts to unlock a smartphone is out of control. Even though to police state that they do not need a warrant needs to be challenged at a higher court. It definitely falls under the 4th Amendment of the Constitution. Just like your house. If you keep the door locked and do not invite a member of law enforcement in then they can’t enter without a warrant. Its is the same analogy as with a smartphone. That’s why we password/bio control access and even encrypt the data stored within it. Unless the person was accused and seen performing a terrorist act which killed numerous people then the use of a dead persons fingers should require a warrant. People are not taking into consideration that several people maybe using that phone. Not just the dead person. Also as soon as it is cracked open, I would question the chain of custody as well. Most Bio systems do require that the finger for instance be at least warm and flaccid as if it were a normal finger. If rigor sets in, the body becomes ridged and the finger will not act or be seen the same as if the person was alive. Especially a frozen body.

“they can’t enter without a warrant” That is not accurate. They can enter under “Suspicion”. If someone calls the police to say you haven’t shown up to work for days (missing person). If they can see/hear/smell from the public property (the street) a crime being committed.

At least in the UK, you don’t own your body after you die, if that isn’t kind of obvious. Therefore it isn’t property in the usual sense, so if we had a Fourth Amendment, it wouldn’t apply to your corpse anyway. (IANAL. I *think* I’ve got this right, but YMMV.) That’s why, in the UK, you can’t “will” your body to a medical school to use it for research or teaching. IIRC all you can do it to make it clear that is your wish while you are alive, and assume that your wish will be respected when you aren’t.

I get the impression that the cops waltzed in while there was a family viewing in progress to swipe the finger. If so, that is pretty darn insensitive on the part of the cops. But, then again, the police anywhere aren’t noted for being particularly sensitive. After chasing the links in the story, I also see that the deceased was not white….score another one for the cops….

Serves them right. A drug investigation is not worth a person’s life. If they wanted to capture the guy they could have shot his tires rather than him.

Comments are closed.

Subscribe to get the latest updates in your inbox.
Which categories are you interested in?
You’re now subscribed!