Law Enforcement Can Legally Compel A Suspect To Use A Finger To Unlock A Smartphone: Cannot Compel A Suspect To Provide The Password To Unlock A Smartphone

From Bloomberg, "The Fingerprint Lock on Your Phone Isn’t Cop-Proof: Law enforcement has an end run around smartphone encryption. For now." by Kartikay Mehrotra:

For the 250 million phones sold around the world with fingerprint authentication since 2013, law enforcement may be able to compel suspects to press their fingers to the devices and unlock them.

With minimal litigation on the books in the U.S., police and prosecutors require only a judge’s blessing on a warrant for a suspect’s fingerprints. So far they’ve used the power sparingly. But as the number of fingerprint scanners in hip pockets grows, district attorneys across the country say the technology is poised to become a major engine of evidence-gathering. "It is likely to be just a matter of time till this does become a primary gateway to accessing phones," says Micheal O’Connor, an Alameda County assistant district attorney in Oakland, Calif.***Los Angeles and Oakland are among the cities that have already granted or received warrants for the use of a finger to unlock a phone. The next step may be a lawsuit that determines whether a fingerprint is off-limits.

Legal scholars say law enforcement is likely to win that fight.