A trial court must find that the proponent of expert witness testimony has set forth adequate evidence that the testimony is based upon reliable methods and will be helpful to the trier of fact. Much has been written regarding the reliability prong since the Supreme Court’s decision in Daubert v. Merrell Dow Pharm., yet a severe prejudice to the criminally accused persists today in some trial courts’ analyses of the often overlooked helpfulness prong. Despite the straight-forward articulation of helpfulness, described as “fit” or mere relevance, some trial courts apply the helpfulness prong differently depending upon whether the expert testimony is offered by a criminal defendant or the government. Reviewing courts must afford great deference to these decisions so steeped in the facts of the case. After discussing the stark contrast between admissibility determinations excluding the defendant’s expert testimony about eyewitness identifications and admitting expert testimony from law enforcement witnesses, this article will analyze the reoccurring issue through the lens of the reviewing courts.
36 Rutgers L. Record 48 (2009).