California judge rules law enforcement can’t force suspects to unlock their iPhone using Face ID or Touch ID

Law enforcement officials can’t force smartphone users to unlock their devices using fingerprints or other biometric features such as facial recognition, according to a Northern California court ruling from last week.

In this particular case, being heard in the U.S. District Court for Northern California, police were seeking a search warrant as part of a Facebook extortion case. The victim in the case was being asked to pay a sum of money to avoid having an “embarrassing” video released to the public.

Law enforcement wanted to use the search warrant to raid the property of people whom they believed to be suspects in the case. Through that raid, they also sought to unlock any phone on the premises with Face ID and Touch ID.

The court said that there was indeed probable cause to grant a search warrant, but that it was denied because the request to force the suspects to unlock their devices using biometric authentication “funs afoul of the Fourth and Fifth Amendments.” From the ruling:

The Government, however, also seeks the authority to compel any individual present at the time of the search to press a finger (including a thumb) or utilize other biometric features, such as facial or iris recognition, for the purposes of unlocking the digital devices found in order to permit a search of the contents as authorized by the search warrant.

For the reasons set forth below, the Court finds that the Government’s request funs afoul of the Fourth and Fifth Amendments and the search warrant application must be DENIED.

In further analysis, the court equated biometric authentication to a passcode rather than something like submitting to a DNA swab. It has been previously established that under the Fifth Amendment, a suspect cannot be compelled to provide the passcode of a device.