Admissibility of Cell-Site Location Information Does Not Require Frye-Mack Hearing

Admissibility of Cell-Site Location Information Does Not Require Frye-Mack Hearing

Because most humans currently walking on Earth have cell phones, finding out where those cell phones were at important times in criminal cases have become critical evidence. One way to cell phone location tracking works is through cell-site location information (CSLI). CSLI refers to data collected as a cell phone connects to nearby towers. This can be used to approximate where the cell phone was located using triangulation. This is different than global positioning system (GPS), which tracks a cell phone’s movements using signals from satellites. In either event, to admit scientific or technical evidence at trial, attorneys may use experts. Before those experts even testify at trial, opposing counsel may challenge whether the evidence is admissible and ask for a Frye-Mack Hearing.

Frye-Mack requires that a novel scientific theory be generally accepted in the relevant scientific community and the evidence offered has foundational reliability. Recently, in State v. Berry, the Minnesota Supreme Court ruled that CSLI was not novel and a Frye-Mack Hearing was not necessary. The court determined that the CSLI evidence had foundational reliability in this case and a hearing on foundational reliability was not necessary either. In this case, the CSLI was used to detect the defendant’s cell phone in relevant locations and times surrounding the offense. First-degree murder charges were on the line.

The defense argued that even if CSLI is not a novel scientific technique it is emerging; and that the proper standard should be whether it is “novel or emerging”. The defense argued that CSLI is growing and developing and therefore emerging. The Minnesota Supreme Court did not agree. It reasoned that there is not separate treatment for novel or emerging. In State v. Harvey, the Minnesota Supreme Court did not treat CSLI as novel or emerging and it felt no reason to do so here.

The supreme court also reviewed whether a Frye-Mack Hearing was necessary on foundational reliability. The district court judge allowed the prosecution’s expert to prove foundational reliability in front of the jury. The judge concluded that the prosecution established foundational reliability but failed to give an explanation. The supreme court determined that the district court judge’s failure to give an explanation was error, but that error was harmless.

Assessing foundational reliability begins by considering the purpose for which it is offered. Next, the court must consider the underlying reliability, consistency, and accuracy of the subject about which the expert is testifying. Then, the lawyer offering the evidence must show that the evidence is reliable in that case. The supreme court decided the prosecution met all its burdens in this circumstance. Importantly, to be admissible, the mere fact that a party is trying to admit CSLI evidence is not enough. There must be foundational reliability of the actual evidence.

The defense did what it could to try and get a new trial in this case. But, the Minnesota Supreme Court did not allow it on these grounds. The defense had alternative arguments for the court to reverse his case for a new trial, such as severing the codefendant’s cases and denying a peremptory challenge during alternate juror selection. Whenever someone loses at trial, especially when the result triggers a lengthy prison sentence, all avenues are explored on appeal. For a consultation at no charge, contact Ambrose Law Firm, PLLC by phone or text at 612-547-3199 or email: ambroselegal@icloud.com.

Robert H. Ambrose is a criminal defense lawyer and DWI lawyer in Minnesota. Super Lawyers named him Super Lawyer this year and a Rising Star the previous six years. He is an adjunct professor at the University of Minnesota Law School. DWI Attorney Woodbury MN, Criminal Defense Attorney St. Paul MN, Criminal Appeals Attorney Minnesota.