Juror Expectations of Forensic Science Evidence

Abstract

The use of forensic science evidence in criminal trials has greatly expanded over the last several decades. Many believe that juries now expect to see scientific evidence in almost all cases. Forensic science programs on television and in other media have proliferated. Some prosecutors believe that jurors often wrongfully acquit guilty defendants when they do not see the kind of evidence they see on television. That idea became known as the “CSI Effect”. We conducted two juror surveys to test that idea. We found that indeed jurors do expect scientific evidence in many criminal cases and may even acquit defendants when the prosecution does not produce any. However we also found that the phenomenon is not related to watching television shows but rather is the result of the “Tech Effect”, which is the product of the dramatic increase in the use of science and technology throughout our society. Attorneys and forensic scientists must adjust to these juror expectations and some possible adjustments are discussed.