In a recent decision in Commonwealth v. Shabazz Augustine, the Massachusetts Supreme Judicial Court ruled that prosecutors seeking access to a defendant's cellular site location information are first required to obtain a search warrant based on probable cause.
In recent years as the popularity of cell phone use has become so widespread, prosecutors have increasingly sought search warrants of a defendant's cell phone records from their cell providers. The information commonly sought not only included a defendant's call list, incoming and outgoing phone calls, text messages and pictures on the phone, but also cell site location information.
Cell site location information, or CSLI, is when a user's cell phone transmits signals to cell phone towers that 'ping' the coordinates of the person's mobile phone. The cell phone towers assist the cell phone in connecting to a call, and if the person moves closer to a different cell tower, the call is automatically transferred to that closer cell tower. By triangulating these pings, the user's cell site location information can reveal a specific geographic location of where the phone was on a particular date and time.
When seeking cell phone records, prosecutors would submit a request pursuant to U.S.C. section 2703, which authorizes production from a cell phone provider to disclose records for a particular subscriber. The problem the Massachusetts Supreme Judicial Court found was that the standard required under section 2703(d) is something "less than probable cause."
In its decision, the court confirmed that the cell site location information, i.e., tracking the location of an individual cell phone user, implicates privacy concerns. In other words, persons do have a reasonable expectation of privacy in their cell site location information and as such, the warrant requirement of Article 14 of the Massachusetts Declaration of Rights applies.
Tracking a person's movement, therefore, through cell phone records and cell site location information, is of the type of privacy interest that would require government to obtain a search warrant establishing probable cause justifying the issuance of the warrant.
So how does this case apply to those defendant's that had their cell site location information obtain prior to this decision?
The court, in announcing the new rule requiring prosecutors to obtain a warrant establishing probable cause in order to be provided with cell site location information, applies prospectively to cases in which a defendant's conviction is not final. In other words, a defendant whose case has not yet been finalized and/or is pending on direct appeal in which this issue was raised may take advantage of this decision. Unfortunately, for those cases where the defendant has exhausted his/her appellate rights, this decision does not help them.