Apple and Google have taken steps recently to let users protect information stored on smartphones even from law enforcement. It turns out there may be a fingerprint-sized gap in that plan.

A Virginia Circuit Court judge ruled Tuesday that police officers cannot force criminal suspects to divulge cellphone passwords, but they can force them to unlock the phone with a fingerprint scanner.

If applied by other courts, the ruling could become important as more device makers incorporate fingerprint readers that can be used as alternatives to passwords. Apple introduced the technology last year in its iPhone 5S and Samsung included it in its Galaxy S5.

When those phones arrived, lawyers said users might be required to unlock the phones with their fingerprints. More recently, Apple and Google said they had changed the encryption scheme on the newest phones using their operating systems so that law enforcement cant retrieve the data. FBI Director James Comey criticized the companies, saying were allowing users to place themselves above the law.

The Fifth Amendment to the U.S. Constitution gives people the right to avoid self-incrimination. That includes divulging secret passwords, Judge Steven C. Frucci ruled. But providing fingerprints and other biometric information is considered outside the protection of the Fifth Amendment, the judge said.

The ruling came in the case of David Baust, an emergency-medical-services captain accused of domestic abuse. Police obtained a search warrant for Bausts phone and asked him to unlock it so they could look for video evidence against him. Baust refused, citing the Fifth Amendment and his right to protect his privacy; Baust said police could search for other, embarrassing items on the phone that are unrelated to the case.

In the wake of Judge Fruccis ruling, Baust does not have to provide his password, but he is required to place his finger on his iPhones fingerprint sensor.

Baust planned to comply Friday morning at a police station in Virginia, his lawyer, James Broccoletti said in an interview. The meeting was postponed because the detective needed to attend to a sick child.

Baust will head to the police station on Monday morning instead, but Broccoletti believes police still may be unable to unlock the phone because it should require a password, in addition to a fingerprint, once it has been shut off.

If they are unable to gain access to the phone, prosecutors in the case could appeal the password ruling to the Virginia court of appeals.

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Judge Rules Suspect Can Be Required To Unlock Phone With Fingerprint