Influence of expert testimony regarding eyewitness accuracy on jury decisions.

Hosch, H. M., Beck, E. L., & McIntyre, P. (1980). Influence of expert testimony regarding eyewitness accuracy on jury decisions. Law and Human Behavior, 4, 287-296.

To determine the influence of expert testimony regarding the general unreliability of eyewitnesses, a two-phase study was conducted. In the first phase, 24 community residents served as jurors on four six-person juries. A burglary case was tried in 120 District Court. El Paso, Texas. Two juries heard all the evidence including the expert testimony of a psychologist and the other two heard all of the testimony except that of the psychologist. During the second phase, 24 student jurors constituting four six-person juries viewed a videotape of the trial. Two of these juries saw the entire proceeding from the first phase including the expert testimony and the remaining two saw all but the expert testimony. All juries acquitted the defendant; however, those who heard the expert testimony significantly lowered their judgments of the accuracy and reliability of eyewitness identification as well as its overall importance to the trial. Further, those juries that heard the expert testimony spent a significantly longer time discussing eyewitness identification as well as other relevant evidence. No differences between community residents and college student juries were obtained.

No impact of jury type (all juries acquitted). Juries hearing expert testimony spent more time talking about eyewitness identification and witness testimony during deliberation and reported eyewitness testimony to be less important.