Earlier this month, a U.S. District Judge limited the testimony of a cell-cite expert.
While I will allow the Government to elicit the opinion from SA Fennern that the location of the defendant’s cell phone was “consistent with” the location of the crime scene at the time of the carjacking, he may not do so until after he has fully explained during direct examination the inherent limitations of the accuracy of his location evidence— namely, the phone can only be placed in the general area of the cell tower sector that it connected to near the time of the carjacking, and that it cannot be placed any more specifically within that sector. During cross examination, the defendant will be allowed to cross examine SA Fennern regarding the limitations of the location evidence that he can offer, based on the historical cell call records. As part of this examination, the defendant will be allowed to use any learned treatises regarding the limitations of using historical cell tower billing records to identify the location of a cell phone that are admissible under Fed. R. Evid. 803(18), consistent with the requirements of that rule (the learned treatise content may be read to the jury, but not admitted as an exhibit.)