CHP using detainee’s fingerprint to unlock phone not a Fifth Amendment violation, appeals court rules

By Joanna Putman
Police1

PASADENA, Calif. — A federal appeals court ruled that police can compel a suspect to unlock their phone using a thumbprint without violating the Fifth Amendment, which protects against self-incrimination, ARS Technica reported.

The case involved Jeremy Travis Payne, a California parolee charged with possession and intent to distribute drugs after a 2021 traffic stop, according to the report. During his arrest, the California Highway Patrol used Payne’s thumb to unlock his phone, an action he contested as a violation of his Fifth Amendment rights.

Payne argued that using biometrics is akin to providing a physical key to a safe but still a testimonial act because it confirms ownership and authentication of the phone’s contents, according to the report. The U.S. Court of Appeals for the 9th Circuit dismissed this, stating, “Payne was never compelled to acknowledge the existence of any incriminating information. He merely had to provide access to a source of potential information.”

“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,” the court explained. “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.”

This decision does not apply universally to all cases involving biometric unlocking, according to the report. “Fifth Amendment questions like this one are highly fact dependent and the line between what is testimonial and what is not is particularly fine,” the court noted.

The 9th Circuit also addressed Payne’s Fourth Amendment claim, ruling that the search of his phone was authorized under a general search condition of his parole, which allowed suspicion less searches of any property under his control, according to the report.