• NinjaKlaus
    +2

    The real reason is that much like fingerprints the 5th Amendment does not currently cover it, meaning if you use touchID or FaceID you can be forced by an officer or court to unlock the phone so that the investigator can read through it. With a password, you can be compelled to give it up but you don't have to as it would be a 5th amendment violation, Although the catch with a password is that if you invoke the 5th and don't unlock it you could still go to prison for contempt of court until you do.