When Your Fingers Do the Talking: D.C. Circuit Rules That Compelled Unlocking of Cellphone With Fingerprint Violates the Fifth Amendment

Given the importance of cellphones to modern life, gaining access to a suspect’s phone is generally a top priority for law enforcement. But once “seized,” a phone’s security measures may present an obstacle for government authorities who then seek to “search” the phone’s contents. While law enforcement can ask the phone’s owner to provide the password, they (generally) cannot compel the person to do so without running afoul of the Fifth Amendment. However, law enforcement frequently — and with court authorization — unlocks devices by simply taking and pressing the phone owner’s finger to the fingerprint scanner or holding the phone up to the person’s face. To justify this approach, the government’s position is that such physical characteristics are not “testimonial” and thus not protected by the Fifth Amendment’s privilege against self-incrimination, just as appearing in a lineup or providing writing samples, voice exemplars, and hair and blood samples are not protected (with some exceptions).

But a recent appellate court decision could substantially narrow law enforcement’s ability to compel a suspect to provide fingerprint access to a cellphone. In January 2025, the D.C. Circuit issued United States v. Brown, 125 F.4th 1186 (D.C. Cir. 2025), in which it held that compelling the defendant to unlock his cellphone violated his Fifth Amendment right against self-incrimination. The D.C. Circuit found that there was no dispute that law enforcement compelled the defendant to open his phone, nor was there any dispute that his opening of the phone was incriminating, because it linked him to the phone’s inculpatory contents. Ultimately, the D.C. Circuit also determined that the defendant’s “disclosing to police [his] way of opening the cellphone and his ability to do so was testimonial,” and therefore his Fifth Amendment rights had been violated.

We explore the Brown decision in detail in our Advisory. But here, we thought it would be useful to focus on some key takeaways.

Takeaways

Going forward, Brown may shape how law enforcement seeks to obtain access to cellphones. Just as importantly, Brown could influence the guardrails that judges reviewing search warrants or suppression motions may impose on the government’s ability to compel a suspect to identify which finger or whose face may open the phone.

Communication surrounding a compelled disclosure may make all the difference regarding whether a disclosure warrants Fifth Amendment protection. Key to the D.C. Circuit’s decision was that because the agent instructed the defendant to open the phone rather than forcing the defendant’s fingers onto the phone, the defendant’s compliance with the order became a “testimonial” act. Thus, what law enforcement authorities communicate before seeking to unlock a cellphone will be critically important to evaluating Fifth Amendment concerns. By the same token, what an individual communicates to law enforcement before and after being compelled to unlock their phone, and whether it was communicated before or after the individual receives a Miranda warning, also will be at issue.

The Fifth Amendment act-of-production doctrine concerns raised in Brown might influence judges in the future as they think through what guardrails might be needed for cellphone seizures. Under the act-of-production doctrine, the production of documents in response to a subpoena is testimonial (and warrants Fifth Amendment protection) because it requires, per United States v. Hubbell, 530 U.S. 27 (2000), “extensive use of [the respondent’s] own mind” and is similar to asking a series of interrogatories about the location of documents. Most often, the act-of-production doctrine arises in the context of a subpoena, where the recipient has an opportunity to assert the doctrine, resist the subpoena, and can then litigate the issue in court. By comparison, there is no such opportunity to assert Fifth Amendment protections in the context of a compelled unlocking of a cellphone.

While the record in Brown was ambiguous regarding the exact circumstances surrounding the compelled unlocking of the defendant’s cellphone, the Fifth Amendment concerns raised by Brown suggest the need for further judicial guidance on what steps, if any, law enforcement could take to ensure the voluntariness of device unlocking.

Check out our recent Advisory for more information on this important case. And please reach out to the authors or any of their colleagues in Arnold & Porter’s White Collar Defense & Investigations practice group for questions on this or any other subject.

© Arnold & Porter Kaye Scholer LLP 2025 All Rights Reserved. This Blog post is intended to be a general summary of the law and does not constitute legal advice. You should consult with counsel to determine applicable legal requirements in a specific fact situation.