In many criminal cases, cell phone tracking data is on the checklist of "must have items" for both law enforcement and the defense, especially in cases where an individual's proximity to the crime or his or her location with respect to certain criminal conduct is in issue. Cell tracking is a technique whereby phone calls allegedly made from one's cell phone may be used to determine the approximate location of the cell phone user when making the calls. The appearance at trial of such evidence is on the uptick. Moreover, the CSI effect of cell site data (CSD) cannot be understated. With the increase in use of such data at trial, can the battle of the experts be far off? Certainly not, and as anticipated, the battle for legal supremacy in court after court has already been engaged nationwide. This article will address the admissibility of expert testimony concerning cell tracking evidence.
'Daubert' Standard
In our adversarial system, it is to be expected that with the evolution of technology comes the battle of the experts concerning its admissibility and the ultimate weight to be accorded it. Although technology changes and evolves, the legal guidelines for the admission of expert testimony concerning such technology has remained constant. In the criminal case involving the admission of expert testimony concerning cell tracking of a defendant's mobile telephone, the government will usually make a proffer concerning the testimony per a motion in limine. Rule 702 of the Federal Rules of Evidence (FRE) requires that the party offering the expert testimony bears the burden of laying the proper foundation, and that party must demonstrate admissibility by a preponderance of the evidence.1
