The ACLU of Massachusetts, together with the Committee for Public Counsel Services (CPCS), filed a supporting brief in Commonwealth v. Johnson, a case challenging law enforcement’s warrantless search of a probationer’s historical GPS location data.

Without seeking or obtaining a warrant, police searched five months of Jamie Johnson’s archived GPS location data, obtained from a monitor he had previously worn as a condition of probation. Johnson’s probation term ended more than a year before this warrantless search.

According to the brief, the Supreme Judicial Court (SJC) and United States Supreme Court have both made clear that new surveillance and tracking technology must not undermine constitutional privacy protections. Yet police investigators and other law enforcement continue to access GPS data of probationers and ex-probationers without any level of individualized suspicion or judicial oversight.

The ACLU of Massachusetts is urging the SJC to confirm that police searches of probationers’ GPS data, like the one that occurred in Johnson’s case, require a warrant based on probable cause.


Jessie Rossman and Matthew Segal (ACLU of Massachusetts); Matthew Spurlock (Committee for Public Counsel Services)