Update on Fingerprints, Phones, and the Fifth Amendment

Can a court order a suspect to use the suspect’s fingerprint to unlock his or her smartphone? Or would that violate the suspect’s Fifth Amendment privilege against self-incrimination? I wrote about that issue here. This post updates the previous one with two new cases and some additional discussion. Background. The Fifth Amendment provides in part that no person may be “compelled in any criminal case to be a witness against himself.” This privilege against self-incrimination applies during the investigative phase of a case as well as at trial. And it applies to the disclosure of information that may lead to incriminating evidence even if the information is not itself directly indicative of guilt. However, it applies only to “testimonial” activity, not to nontestimonial actions like providing fingerprints, blood samples, or voice exemplars. The “act of producing” evidence that is not itself testimonial “may have a compelled testimonial aspect,” as when the act of producing the evidence constitutes an admission that the evidence was in the suspect’s possession or control. United States v. Hubbell, 530 U.S. 27 (2000) (ruling that tax fraud charges must be dismissed because the charges were based on documents the defendant produced in response to a grand jury subpoena; the defendant’s act of producing the documents was testimonial because “the collection and production of the materials demanded was tantamount to answering a series of interrogatories asking a witness to disclose the existence and location of” any incriminating documents; “[t]he assembly of those documents was like telling an inquisitor [...]