[DugwayDuke]

Political Junkie Too wrote: “In that case, they already have the weapon with the fingerprint on it, so they have reasonable cause to ask for the person’s fingerprint.”

Why do they have reasonable cause to ask for a specific person’s fingerprint? Just because there is a print on a handgun? Why John Doe’s print? Why not Edward John’s print? Can the police just stop random people and make them give a print?

[Political Junkie Too]

First, let's agree that we're dealing with a hypothetical here, so we're free to make up our own facts.

You analogized a gun with fingerprints. In the case of the phone, that it was the suspect's phone is not in doubt. So the analogy assumes that the gun with the fingerprint belongs to the person being asked to provide a fingerprint, same as with the phone.

Now, do the police have probable cause to ask the owner of a gun to provide a fingerprint to match one found on a gun? I think so, at the very least to rule out the owner as the last to touch the gun.

Now let's change the hypothetical slightly. The owner of a gun already has fingerprints on file from the purchase of the gun, so the police would already have checked that without the gun owner's involvement. So let's say the the gun was found in the possession of someone else. Do the police have probable cause to ask the possessor of a gun to provide a fingerprint to match one found on a gun? Again, I think so.

This would not be a random person stopped on the street, - would be someone found in the vicinity of the gun/phone, with a probable connection to it.

Finally, checking a fingerprint on a gun does nothing to alter the state of the gun, but swiping the fingerprint on the phone changes the state of the phone.

-PJ

[itsahoot]

Can the police just stop random people and make them give a print?

I think virtually every state requires a thumb print be included on your driving license.