Herndon Testimony on Polygraph Interpretation Assuming Mental Competence
Considering other phases of Dr. Beavers’ testimony, Herndon stated that, based on the hypothesis that Ruby was mentally competent and sound, the charts could be interpreted to indicate that there was no area of deception present with regard to his responses to the relevant questions during the polygraph examination.
Dr. Beavers’ Exceptions for Polygraph Questions on Family and Counsel Safety
While stating his opinion that Ruby was in touch with reality and understood the questions and answers, Dr. Beavers excepted two questions where he concluded that Ruby’s underlying delusional state took hold. Those questions related to the safety of Ruby’s family and his defense counsel. Ruby had answered these questions in the preliminary session by stating that he felt his family and defense counsel were in danger, but he did not answer either question when the polygraph was activated. Dr. Beavers interpreted Ruby’s failure to answer as a reflection of “internal struggle as to just what was reality.”
Dr. Beavers’ Testimony That Polygraph Test Was Not Injurious
Dr. Beavers testified that the polygraph test was not injurious to Ruby’s mental or physical condition.
Commission Approval of Ruby’s Requested Polygraph Examination
Because Ruby not only volunteered but insisted upon taking a polygraph examination, the Commission agreed to the examination.
J. Edgar Hoover’s Statement on Polygraph Limitations
FBI Director J. Edgar Hoover commented on the polygraph examination, noting that the polygraph is not in fact a “lie detector” but is designed to record emotional responses in the form of physiological variations which may indicate and accompany deception. The FBI felt that the polygraph technique is not sufficiently precise to permit absolute judgements of deception or truth without qualifications, and noted that one of its limitations relates to the mental fitness and condition of the examinee to be tested.
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