In January 2025, the U.S. Court of Appeals for the District of Columbia Circuit issued a landmark ruling that has the potential to redefine constitutional rights in the digital era.
The case, United States v. Brown, hinged on the FBI’s actions in compelling a defendant to unlock his smartphone using his thumbprint, a maneuver deemed a violation of the Fifth Amendment.
This decision prompted a significant challenge to the intersection of biometric security measures—like fingerprints and facial recognition—with protections against self-incrimination.
At the heart of the case is Peter J. Schwartz, a 49-year-old man from Pennsylvania, who gained notoriety as one of the most heavily sentenced and convicted individuals from the January 6, 2021, attack on the U.S. Capitol.
Convicted of nine felonies and two misdemeanors, Schwartz’s offenses included assaulting federal officers with a folding chair and pepper spray, culminating in a 170-month federal prison sentence in 2023.
During a search of his home, FBI agents discovered a cellphone in Schwartz’s bedroom.
When he refused to provide a numeric passcode, they compelled him to unlock the phone using his fingerprint, which subsequently revealed incriminating evidence used against him in court.
On appeal, Schwartz contended that unlocking the phone with his fingerprint constituted a testimonial act, thereby violating his Fifth Amendment right against self-incrimination.
The D.C. Circuit agreed with this assertion, drawing lines of reasoning that challenge historical interpretations of what constitutes testimonial evidence.
Historically, the Fifth Amendment has prohibited compulsion to provide spoken or written confessions, but challenges arise when considering physical acts, such as the use of biometrics to gain access to digital devices.
The Supreme Court has long differentiated between “testimonial” evidence—communications revealing inner thoughts—and “non-testimonial” evidence such as compulsory blood samples, handwriting, or fingerprints used in the booking process.
However, the D.C. Circuit argued that employing a fingerprint to unlock a smartphone represents a significant departure from traditional compulsory fingerprinting during arrests.
The court maintained that biometric unlocking goes beyond mere identification, as it implicates knowledge and control over the device itself.
Schwartz’s compliance in using his thumbprint was compared to verbally answering a question, as both acts confirm ownership and access to the device’s contents.
This nuanced view places biometric acts within the realm of the “act of production” doctrine, suggesting that compelled evidence can indeed be testimonial if the act conveys factual assertions.
In this context, fingerprints become more than biological identifiers; they transform into a silent admission of fact and knowledge.
Contrastingly, just months prior to the Brown ruling, the Ninth Circuit Court of Appeals issued a conflicting decision in United States v. Payne.
In that case, a parolee was compelled to use his fingerprint to unlock his phone.
The Ninth Circuit regarded this act as non-testimonial, likening it to non-invasive procedures such as compelled blood draws and handwriting samples.
Relying heavily on precedents like Schmerber v. California and Doe v. United States, the Ninth Circuit maintained that, because such actions require no cognitive effort, they do not meet the criteria for Fifth Amendment protection.
The stark divergence between the D.C. and Ninth Circuits has resulted in a “circuit split,” which is likely to attract the attention of the U.S. Supreme Court.
Legal experts caution that the implications of these contrasting rulings could dramatically affect how courts across the nation approach cases involving compelled access to data-rich devices.
The significance of the Brown decision extends beyond criminal law; in the digital age, smartphones can be considered extensions of ourselves, housing everything from personal messages and photos to financial records and health information.
Unlocking such devices can disclose more intimate personal details than a traditional home search could have, starkly contrasting with the constraints placed by the Bill of Rights.
Should the D.C. Circuit’s perspective prevail, methods of biometric security, including Apple’s Face ID, Samsung’s iris scans, and various fingerprint unlock systems, would be afforded constitutional protections when employed to safeguard personal data.
This outcome would restrict law enforcement’s ability to compel access to devices without securing a warrant or obtaining consent.
Furthermore, such a ruling would align biometric authentication with established legal protections related to memorized passcodes.
Courts have long upheld that revealing a memorized passcode qualifies as testimonial; thus, delineating between different methods of unlocking devices appears arbitrary and could undermine digital privacy rights overall.
The ramifications of Brown also extend to activities at U.S. borders, where Customs and Border Protection (CBP) officers enjoy broader legal authority compared to domestic law enforcement.
At the border, agents are empowered to inspect electronic devices without a warrant, following the “border search exception.”
While CBP cannot compel individuals to disclose passcodes legally, the agency increasingly utilizes biometric tools to achieve access.
There are growing reports of CBP officers detaining travelers and exerting pressure—particularly on non-citizens—to compel them to unlock their devices using fingerprint or facial recognition methods.
This practice raises serious concerns about coercion and the erosion of constitutional protections, particularly relating to viewpoint-targeted searches.
Individuals such as attorneys, journalists, and political dissidents have reportedly been singled out for their device searches after expressing critical opinions about the government.
Should the D.C. Circuit find biometric unlocking to be a testimonial act, routine CBP practices may be deemed unconstitutional, especially in cases of targeting based on political viewpoint.
As the legal landscape becomes increasingly complex, another pressing question emerges: Can law enforcement circumvent the Fifth Amendment by spoofing biometric security features?
Theoretically, the answer is yes.
In practice, however, successfully spoofing security features is much more complicated.
A 2020 study by cybersecurity researchers at Cisco Talos revealed that spoofing a fingerprint could unlock smartphones approximately 80 percent of the time, although the methodology varied significantly based on the phone model, the type of sensor, and the version of software in use.
Modern devices increasingly incorporate “liveness detection” mechanisms to verify that the biometric is being presented by a living person.
Some models resist spoofing even when the fingerprint mold is meticulously crafted, and regular security updates from manufacturers further complicate the feasibility of spoofing as a viable law enforcement strategy.
Even if a spoofed biometric succeeds, it raises significant Fourth Amendment concerns, as utilizing someone else’s biometric data without their consent could constitute an unreasonable search.
Given the conflicting opinions emerging from both the D.C. and Ninth Circuits, the legal community anticipates the Supreme Court’s intervention.
This forthcoming ruling is poised to not only resolve the immediate legal conflict but will also set a precedent that addresses how digital privacy aligns with the long-standing principles enshrined in the Constitution.
Some legal scholars predict that the Supreme Court may echo its reasoning in Carpenter v. United States, which mandated that law enforcement obtain warrants to access historical cell site location data.
In this decision, the Court recognized that advancing technologies necessitate evolving interpretations of privacy rights.
Should this rationale prevail, it could place biometric unlocking firmly under the protections of the Fifth Amendment.
On the other hand, some experts warn that the Roberts Court may prefer to issue a narrow ruling contingent upon contextual factors, such as custodial status or whether a warrant is present.
This introduces a larger philosophical debate: Does the Constitution evolve alongside technological advancements, or is its original text strictly confined to its historical context?
The D.C. Circuit’s ruling in United States v. Brown represents a pivotal development in constitutional law.
By classifying biometric unlocking as a testimonial act, the court acknowledges the reality that, in today’s digital age, our bodies serve as keys to our most private lives.
As the act of unlocking a smartphone blurs the line with the act of confessing, it becomes clear that the Fifth Amendment must evolve to remain relevant.
The broader implications of this ruling will likely echo through American legal systems, as citizens await a definitive decision from the Supreme Court.
image source from：https://www.biometricupdate.com/202506/biometric-privacy-on-trial-the-constitutional-stakes-in-united-states-v-brown
