Opinion ID: 388130
Heading Depth: 2
Heading Rank: 1

Heading: The Exculpatory Significance of the Defendant's Polygraph Evidence

Text: 18 It seems obvious that evidence of a favorable polygraph examination taken by the defendant would have been of great importance to the defense of the Wisconsin charge. The entire prosecution case rested on the testimony of the victim as to the identity of his assailant. Given the problems inherent in such an identification, see O'Connor, That's the Man: A Sobering Study of Eyewitness Identification and the Polygraph, 49 St. John's L.Rev. 1, 26-27 (1974), particularly an identification based upon a short observation in the dark while being knocked to the ground, the state's case was far from overwhelming. The defendant took the stand and denied any involvement in the crime. His credibility was the primary issue before the jury, and the jury's verdict reflects its decision not to credit his testimony. Under these circumstances, a polygraph examination that bolstered the defendant's credibility might easily have been decisive in securing an acquittal. Although we do not wish to become embroiled in a numbers game, we note that even the most ardent detractors from the validity of polygraph evidence concede a degree of reliability of 70% or higher for properly administered examinations. 7 Further, a large portion of this 30% error rate includes tests that yield inconclusive results results that cannot fairly be described as erroneous. 8 Where credibility is as critical as in the instant case, the circumstances are such as to make the polygraph evidence materially exculpatory within the meaning of the Constitution. See Westen, Compulsory Process II, 74 U.Mich.L.Rev. 191, 197 (1975). 19