A person suspected of a crime cannot be compelled to divulge to authorities the passcode that would unlock his smartphone. To allow this would be a clear violation of the Fifth Amendment to the Constitution.

But a fingerprint doesn't share those same protections. At least according to a recent ruling from a Circuit Court judge in Virginia, who found that compelling a suspect to unlock his fingerprint-protected smartphone is just fine and dandy.

There's some logic here, but it's pretty badly flawed. The thinking behind the decision: The Fifth Amendment to the Constitution states that an individual cannot be forced to testify against himself. As such, compelling someone to fork over a smartphone's passcode -- which would amount to testimony -- would violate the Fifth Amendment.

But a fingerprint, the judge said, is another story. It's more like a key, which the law has long allowed authorities to obtain from a criminal suspect.

While one can understand the legal distinction that forms the basis for the ruling, it doesn't long hold up under scrutiny.

The Fifth Amendment states, in part: "No person shall be ... compelled in any criminal case to be a witness against himself." This is the right that people are invoking when they refuse to testify on the grounds that they may incriminate themselves.

So legally, a passcode is a kind of testimony, but a key isn't.

Which is fine as far as it goes. But this is exactly where the judge went wrong.

A fingerprint can be akin to a key -- or not. In the matter at hand, what it is, in effect, is a replacement for a passcode, which is information that used to be inside the user's head. If we'd once unlocked our phones with physical keys -- like those that open a door or start the car -- the reasoning would make sense, as the fingerprint would be a replacement for same.

But that's simply not the case. We used to unlock our phones with information in our heads. And that information was protected by the Fifth Amendment. One's fingerprint, simply a replacement for the old memorized pass code, ought reasonably be afforded that same protection.

Read the original here:

Editorial: Applying the Fifth Amendment in the era of smartphones