Cell phones and the 5th Amendment right against self-incrimination

Photo Illustration by Jaren Wilkey/BYU.

Data security technologies, like those used on both Apple and Samsung cell phones, continue to provide consumers with features aimed at increasing their data security.  Apple says iPhone users unlock their phones an average 80 times a day. Samsung’s newest device allows users to unlock their phones with an on-screen fingerprint scanner.  Apple has included fingerprint technology (Touch ID) on their phones since 2013 and now offers Face ID, which allows users to unlock certain iPhones by simply looking at their screen. Face ID creates a 3-D map of the phone’s owner’s face with over 30,000 data points that secures the device so that it may only be unlocked after it confirms that its owner is trying to unlock it. Courts have referred to this information as biometric data, whether that be an individual’s fingerprint or the data that enables their device to recognize their face.

However, as consumers continue to buy cell phones with increased data privacy features, courts have indeterminately applied constitutional law—and the protections that follow—to the increased availability of citizen’s most personal data.

“Courts have an obligation to safeguard constitutional rights and cannot permit those rights to be diminished merely due to the advancement of technology.”

In the United States Supreme Courts’ decision in Riley v. California, the Court recognized the grave invasion of privacy represented by the search of a person’s cell phone.  The Court held that the police must obtain a warrant before searching a cell phone found incident to a lawful arrest.  The Court eloquently stated that: “a cell phone search would typically expose to the government far more than the most exhaustive search of a house: A phone not only contains in digital form many sensitive records previously found in the home; it also contains a broad array of private information never found in a home in any form—unless the phone is.”

The question of whether the police can compel an individual to unlock their cell phone using biometric data not only implicates the Fourth Amendment to the United States Constitution—which protects individuals from unreasonable searches and seizures—but also a citizens’ Fifth Amendment right as well. The Fifth Amendment to the United States Constitution provides that: “[n]o person . . . shall be compelled in any criminal case to be a witness against himself . . . .”

In Doe v. United States, the United States Supreme Court held that a combination to a wall safe is considered testimonial because recalling the passcode forces a defendant to reveal a product of his mind. 

When considering the constitutionality of compelling a person to unlock their phone with biometric data, the relevant inquiry is whether an act would require the compulsion of a testimonial communication that is incriminating.  In Doe v. United States, the Supreme Court held that a combination to a wall safe is considered testimonial because recalling the passcode forces a defendant to reveal a product of his mind.  In 2018, the United States District Court for the District of Columbia found the distinction between a numerical passcode that would only be known and entered as a product of a suspect’s mind, and a fingerprint passcode which does not require any mental effort of the suspect dispositive in its determination that compulsion of a fingerprint passcode would not implicate the suspect’s Fifth Amendment right against self-incrimination.  Although, as noted by Brett Max Kaufman, a staff attorney with the ACLU Center for Democracy “[a]s most iPhone users know, we use our thumb- and face-prints for the same purpose we manually enter a code: to unlock our phones.”

The District Court for the District of Columbia allowed the compulsion of a fingerprint password on the grounds that it is not testimonial.  The United States Supreme Court in Fisher v. United States created an exception to the general rule provided in Doe.  The exception is known as the “Doctrine of Forgone Conclusion.” It provides that the government may compel production of a testimonial password if it finds that the government knows with reasonable particularity the location, possession, and authenticity of that evidence.

In 2016, a Florida District Court further withered away at the Fifth Amendment protections from Fisherand Doe.  The court held in State v. Stahl that for the “Doctrine of Forgone Conclusion” to apply, the State need not establish possession, authenticity, nor the location of evidence in order to compel production of a suspect’s passcode, but instead must only prove that the cellphone could be associated with the defendant.

Judge Westmore­­ reasoned . . . that “biometric features serve the same purpose of a passcode, which is to secure the owner’s consent, pragmatically rendering [a number passcode and a biometric passcode] functionally equivalent.”

In 2019, a United States Magistrate Judge for the Northern District of California denied a government application for a search warrant to “compel any individual present at the time of the search to press a finger (including a thumb) or utilize other biometric features, such as facial or iris recognition, for the purposes of unlocking the digital devices found in order to permit a search of the contents as authorized by the search warrant.”  In her opinion, Magistrate Judge Westmore reasoned that “biometric features serve the same purpose of a passcode, which is to secure the owner’s consent, pragmatically rendering [a number passcode and a biometric passcode] functionally equivalent.” Judge Westmore also found that that the “Forgone Conclusion Doctrine” did not apply because, due to the large amounts of data and sensitive records present on any given individual’s cell phone, the full contents could not be anticipated by law enforcement acting on behalf of the government; therefore, the requisite prior knowledge that the suspect possesses the evidence on their phone is inherently lacking.

Courts have varied on the issue of whether compelling suspects to provide biometric passwords to their phones violates their Fifth Amendment right against self-incrimination and a definitive rule has yet to be established.  The issue is ripe for the United States Supreme Court, as the Court typically hears cases involving issues that have created split decisions among jurisdictions. However, until the Supreme Court provides a bright-line rule on the issue, maybe it would be best for individuals to forego the convenience of Touch ID or Face ID, instead choosing to protect their cell phone data with old-school numerical passcodes.

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About Michelle Nunes (3 Articles)
Michelle is the former Managing Editor for the Campbell Law Observer. A North Carolina native, she was born and raised in Raleigh. Her love for the mountains drew her to study at Appalachian State University where she obtained a Bachelor of Science in Criminal Justice with a minor in English. Before beginning law school, Michelle worked for civil litigation firm, Blanchard, Miller, Lewis & Isley, as an Administrative Assistant. As a second-year student, she worked for Sparrow Law Firm as an Administrative Case Manager. Michelle also interned with the Office of the Federal Public Defender for the Eastern District of North Carolina. She is especially passionate about criminal law and procedure, constitutional jurisprudence, and privacy law.
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