Minnesota Lawyer Blogs
Home – Practice Areas – Blogs – Phone Fingerprint
First your finger, is your face next?
As smartphone security technology has increased, the simplicity of accessing your smartphone with the touch of a finger or a glance of your eyes appears to have opened the door to law enforcement searches of criminal defendants’ digital devices.
In United States’ first major criminal law decision of its kind, Minnesota’s highest court recently ruled that law enforcement officers can make you unlock your phone if you have fingerprint identification activated. With the advent of face-recognition technology, it’s possible that law enforcement could soon require you to look at your phone in order to unlock its contents.
Meanwhile, a memorized passcode may still be protected.
The Diamond Decision
In State v. Diamond – handed down in January – the Minnesota Supreme Court was tasked with deciding whether the act of pressing a finger against a phone was protected by the Fifth Amendment right to not incriminate oneself. Police had arrested the defendant and noticed that his phone was protected by fingerprint identification.
Police officers asked him to provide his fingerprint to unlock the phone. The defendant refused, asserting his Fifth Amendment privilege against self-incrimination. A judge ultimately ordered the defendant to provide the fingerprint, and the defendant appealed.
The Supreme Court held that because a fingerprint merely “demonstrated… physical characteristics and did not communicate assertions of fact from [the] mind,” the “act of providing a fingerprint to the police to unlock a cellphone was not a testimonial communication protected by the Fifth Amendment.
In handing down the decision, the Court explicitly noted, “We do not decide whether providing a password is a testimonial communication.” However, in differentiating a fingerprint from a password, the Court cited several cases in support of the notion that a memorized password is testimonial and subject to Fifth Amendment protection.
What next?
After the Minnesota Supreme Court’s decision in Diamond, it’s clear that the Fifth Amendment does not afford you the privilege of refusing to unlock your phone with a fingerprint. By analogy, it’s likely that facial recognition technology would likely be considered the same kind of “physical characteristics” that do not “communicate assertions of fact from [the] mind.”
Meanwhile, courts outside of Minnesota largely have come down in favor of memorized passwords falling within the Fifth Amendment privilege. Until the U.S. or Minnesota Supreme Court makes a ruling one way or another, memorized passwords appear to be the most secure form of protection against a law enforcement search of your phone.
Pro tip: iPhone users running iOS 11 or higher can quickly press the sleep/wake button 5 times to require entry of a password. Just sayin’.