Emerging Legal Issues in Compelling the Use of One’s Fingerprint to Open a Phone

• The use of “biometrics” and the compelled opening of private devices  
• Good faith in the execution of a search warrant absent settled law to the contrary  
• The “foregone conclusion” doctrine  
• Communications search warrants for cellphones  
• Compelled use of one’s finger to unlock a cellphone and Fourth Amendment, Fifth Amendment and due process issues 

A separate statement of probable cause, and a request to use reasonable force if necessary, becomes a part of a search warrant when specifically incorporated by reference. An officer’s good faith, absent settled law to the contrary, allows for the execution of a search warrant even if the warrant is later found to be legally inadequate. The use of a suspect’s fingerprint to unlock his cellphone, the contents of the cellphone being non-testimonial, does not violate the subject’s Fifth Amendment privilege against self-incrimination.  

Also, with law enforcement already knowing what the cellphone contains, the “foregone conclusion doctrine” applies, allowing law enforcement to search and seize the cellphone’s contents. A suspect’s due process rights are not violated by a law enforcement officer forcing a suspect to use his fingerprint to open his cellphone when the force used is minimal and ....