Japanese police have begun using court-issued physical-inspection warrants to compel facial unlocking of smartphones in investigations where officers believe evidence could be deleted remotely.
Osaka Prefectural Police used the approach while investigating members of Natural, an illegal employment-placement group whose communications app allowed remote deletion of messages. Officers sought access to devices during a search-and-seizure operation so they could preserve information before it was erased.
The warrant instructed officers to ask a suspect to unlock the phone and, if the person refused, hold the person’s face between 20 and 50 centimeters from the device for about one second. The procedure was designed to trigger the phone’s facial authentication without requiring the suspect to disclose a passcode.
Physical-inspection warrants have more commonly been used in Japan to examine a person’s body for evidence such as injection marks in drug investigations or injuries in assault cases. Applying the same legal instrument to a face or eyes for device authentication extends it into digital evidence collection.
A senior National Police Agency official said courts are expected to authorize the method only in highly organized cases with a substantial risk that evidence will be destroyed. Practical limits also remain: a face unlock may fail if the user closes the eyes, and forcing them open would raise a separate question about the degree of force officers may use.
Daisuke Midori, a law professor at Hitotsubashi University, said the warrant is not necessarily improper but warned that its execution could exceed socially accepted limits on force. The legal issue centers on the difference between compelling a person to reveal memorized information and using a physical characteristic to operate a device.
The development comes as phones hold a growing share of people’s official credentials and authentication tools. Japan recently became the first country outside the United States to place a national identity credential in Apple Wallet. Japanese companies have also tested facial recognition over mobile networks for remote identification.
In the Osaka case, the physical-inspection warrant gave police a defined legal route to use the suspect’s face for access. It also places biometric device unlocking within the rules governing searches of a person’s body, rather than treating it solely as a demand for digital credentials.
Sources: SBS News
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By Ji-seo Kim
