How ‘Pleading the Fifth’ Has Become More Difficult in the Smartphone Era: Why a State Appeals Court Says Unlocking a Smartphone with a Fingerprint is Different Than a Passcode

January 31, 2017

Three years ago, Apple released an iPhone that changed the way users were able to protect their data.  The new smartphone features a fingerprint ID biometric system, allowing users to scan their fingerprint as a method of securing their smartphone and the data inside, as opposed to your typical every-day numerical or alphabetical passcode.  Many believe a fingerprint is more unique than a passcode, and a better way to keep thieves and hackers from breaking into a phone with the rise of hacker technologies.  In today’s era of smartphone capabilities, it’s also much easier for users to simply hold their finger over the “home” button to enter their phone, instead of having to re-enter a passcode each time they wish to use a different feature.

However, “[c]ellphone fingerprint passcodes weren’t on James Madison’s mind when he authored the Fifth Amendment, a constitutional protection with roots in preventing torture by barring self-incriminating testimonials in court cases.

This ultimately explains the Minnesota Appeals Court ruling against a man who was forced to use his fingerprint to unlock his phone by police.  In State v. Diamond, the government sought an order compelling the defendant to unlock his smartphone with his fingerprint after he was convicted of burglary.  When Diamond refused to comply, the trial court ruled that Diamond had no Fifth Amendment privilege available to him, and that by refusing the order he would be found in contempt of court.  Diamond ultimately provided his fingerprint, and the police immediately searched his cellphone for evidence of criminal activity.  On appeal, Diamond argued that the government violated his Fifth Amendment rights because he “was required to identify for the police which of his fingerprints would open the phone,” and that “this requirement compelled a testimonial communication.”
The court rejected this argument and concluded that forcing a person to place a particular finger on a phone does not trigger the Fifth Amendment because it is not “testimonial.”  Under the Fifth Amendment, defendants cannot be compelled to provide self-incriminating testimony (“what you know”), but that giving a fingerprint (“what you are”) for the purposes of identification is allowed. The court reasons that by being forced to produce his fingerprint, Diamond was not required to disclose any knowledge he may have, or speak to his own guilt.  This can be distinguished from cases in which defendants have been ordered to decrypt a hard drive or produce a combination for a safe, and is more synonymous with an order to produce the key to a locked safe.  The requirements of the first scenarios “involve a level of knowledge and mental capacity that is not present in ordering Diamond to place his fingerprint on his cellphone.”  But instead, the task that Diamond was compelled to perform “is no more testimonial than furnishing a blood sample, providing handwriting or voice exemplars, standing in a lineup, or wearing particular clothing” – all situations where the court ultimately decided that there was no Fifth Amendment violation.
While the initial decision to hold that a fingerprint is synonymous to a key that opens a safe, or standing in a lineup, both of which do not require any actual testimony, Diamond’s main issue is what is contained in the now-unlocked device that might become incriminating.  He pointed to In re Grand Jury Subpoena to support his argument that his fingerprint was, in fact, testimonial.  In In re Grand Jury, the court held that “requiring the defendant to decrypt and produce the contents of a computer’s hard drive, when it was unknown whether any documents were even on the hard drive, would be tantamount to testimony by [the defendant] of his knowledge of the existence and location of potentially incriminating files.”  The court says the process that unlocked the smartphone – the fingerprint – requires no knowledge or mental capacity, and that the end result – the production of evidence against oneself – is different because of the part of the body used to obtain access – the finger vs. the brain.
The Minnesota Appeals Court decision has caused a great deal of confusion, as it seems Diamond would still be demonstrating some form of control over the device and its contents, rendering his fingerprint to still serve as somewhat of a testimonial act, even if it does not rise to the mental level of communicating a password or a combination.  The decision calls into question whether or not a four-digit passcode would be “less testimonial” than a nine-digit alphanumeric passcode, if all that is examined if mental effort to determine what is “testimonial.” However, the precedent that has been established is that fingerprints are less protective of defendants’ Fifth Amendment rights than are passwords.