Beginning in the mid-2000s numerous states, including North Carolina, adopted “Jessica’s” laws requiring GPS monitoring of certain sex offenders. Since then, as GPS has become more common and more inexpensive, state and local governments have begun using it to monitor other categories and kinds of offenders. Most recently, NCSL reports that some states are using it as an alternative to pretrial detention.
In a per curiam (unauthored) opinion the Supreme Court concluded in Grady v. North Carolina that satellite-based monitoring (SBM) for a recidivist sex offender is a “search” within the meaning of the Fourth Amendment. The Court left it to the lower court to decide whether it is an unreasonable, and therefore unconstitutional, search.