I thinks it's likely that you could "check to see if your fingerprint matches the one in your phone". But that is totally different than using your fingerprint to unlock the device and then take information off the device to prosecute you. However, it has been found a few times that biometrics aren't really protected. But in many cases a password can be. Because you can't be compelled to incriminate yourself with your own testimony per the 5th amendment.
