Ars Technica: “The US Constitution’s Fifth Amendment protection against self-incrimination does not prohibit police officers from forcing a suspect to unlock a phone with a thumbprint scan, a federal appeals court ruled yesterday. The ruling does not apply to all cases in which biometrics are used to unlock an electronic device but is a significant decision in an unsettled area of the law. The US Court of Appeals for the 9th Circuit had to grapple with the question of “whether the compelled use of Payne’s thumb to unlock his phone was testimonial,” the ruling in United States v. Jeremy Travis Payne said. “To date, neither the Supreme Court nor any of our sister circuits have addressed whether the compelled use of a biometric to unlock an electronic device is testimonial.” A three-judge panel at the 9th Circuit ruled unanimously against Payne, affirming a US District Court’s denial of Payne’s motion to suppress evidence. Payne was a California parolee who was arrested by California Highway Patrol (CHP) after a 2021 traffic stop and charged with possession with intent to distribute fentanyl, fluorofentanyl, and cocaine. There was a dispute in District Court over whether a CHP officer “forcibly used Payne’s thumb to unlock the phone.” But for the purposes of Payne’s appeal, the government “accepted the defendant’s version of the facts, i.e., ‘that defendant’s thumbprint was compelled.'” Payne’s Fifth Amendment claim “rests entirely on whether the use of his thumb implicitly related certain facts to officers such that he can avail himself of the privilege against self-incrimination,” the ruling said. Judges rejected his claim, holding “that the compelled use of Payne’s thumb to unlock his phone (which he had already identified for the officers) required no cognitive exertion, placing it firmly in the same category as a blood draw or fingerprint taken at booking.” “When Officer Coddington used Payne’s thumb to unlock his phone—which he could have accomplished even if Payne had been unconscious—he did not intrude on the contents of Payne’s mind,” the court also said…”