But if a person refuses to give up his phone and police believe it contains evidence of a crime, then officers can seize it. Grubbs said a search warrant isn’t needed at the time officers seize the phone, but one is in order to download information from the device.
The federal judge in Los Angeles may have moved quickly to
sign and execute the warrant because there’s only a 48-hour window during which an iPhone will accept its user’s fingerprints. After that window—or after a restart—the phone will require a PIN or passcode to unlock.
The Fifth Amendment, which protects people from incriminating themselves during legal proceedings, prevents the government from compelling someone to turn over a memorized PIN or passcode. But fingerprints, like other biometric indicators—DNA, handwriting samples, your likeness—have long been considered fair game, because they don’t reveal anything in your mind.
The legal position on using Touch ID to unlock a phone seems clearer, where
multiple court
rulings have
decided that a fingerprint is the equivalent of a safe key, and police are free to use a suspect’s fingerprint to unlock the device. You can read a 2014 analysis of the legal position of both forms of protection
here.