This morn­ing, the Supreme Court issued a unan­i­mous deci­sion in United States v. Jones, which we cov­ered in Novem­ber. As a reminder, this case involved law enforce­ment offi­cers sur­rep­ti­tiously installing a global posi­tion­ing satel­lite track­ing device on a suspect’s vehicle.

While the deci­sion was unan­i­mous, there were three dif­fer­ing opin­ions, rang­ing from Jus­tice Scalia’s (the major­ity, and most mod­er­ate, opin­ion), to Jus­tice Sotomayor’s.

The Court held that attach­ing such a device con­sti­tutes a search under the Fourth Amend­ment, because it vio­lates the suspect’s rea­son­able expec­ta­tion of pri­vacy. As such, a track­ing device requires a warrant.

What was less clear was the details of just how far law enforce­ment offi­cers can go before they need a war­rant. Jus­tice Scalia refused to com­ment on the rea­son­able­ness of the search itself, since the lower courts did not address that issue. For this rea­son, we can expect future cases to be argued before the Court, involv­ing the inter­sec­tion of GPS devices and rea­son­able suspicion.