A Survey of Federal and State Standards for the Admission of Expert Testimony on the Reliability of Eyewitnesses

George Vallas

Independent 2011 American Journal of Criminal Law, Vol. 39, No. 1, Fall 2011 Abstract: Eyewitness testimony is indispensible to the proper functioning of the criminal justice system. However, as Justice Frankfurter famously observed: “The vagaries of eyewitness identification are well-known; the annals of criminal law are rife with instances of mistaken identification.” Social scientists, legal commentators, and even courts have long been skeptical of eyewitness testimony. Developments in forensic testing have established beyond any doubt that eyewitness testimony has the potential to be dangerously unreliable, and eyewitness misidentification remains the leading cause of false convictions in the United States.

The use of psychological and behavioral science experts during trials would alleviate this danger to some degree. Expert eyewitness testimony serves two principle goals: it should both inform jurors that eyewitnesses are significantly less reliable than common sense suggests, and also should educate jurors about the nature of human memory and specific variables that affect the accuracy of identifications. Ideally, such testimony will allow jurors to continue relying on eyewitness testimony when appropriate, while at the same time evaluating its reliability more effectively.

Courts, however, have historically been reluctant to permit the use of eyewitness experts. Although the trend over the past several decades has been toward a greater reliance on experts, standards still vary among state and federal jurisdictions. This Article will attempt to provide a comprehensive survey of the standards for the admission of eyewitness expert testimony in federal and state courts. It will proceed in five parts: Part II will discuss the role of eyewitness testimony in false convictions; Part III will evaluate the specific factors that contribute to the inaccuracy of eyewitness identifications; Part IV will provide a brief overview of the general standards governing the admission of expert testimony in state and federal courts; Part V will determine how these standards are applied to eyewitness experts in particular; and, finally, Part VI will evaluate the various judicial approaches and provide normative suggestions for the proper use of expert eyewitness testimony.