The constitution has been interpreted to allow the police to force your finger onto an inkpad for fingerprints. That decision was extended to allow the police t

The constitution has been interpreted to allow the police to force your finger onto an inkpad for fingerprints. That decision was extended to allow the police to force your finger onto a biometric reader. The 5th Amendment has been (so far) interpreted to only limit things that require conscious thought, such as remembering a password and speaking it or typing it.