The fact that polygraph test results are not admissible in a court of law has not deterred an ongoing debate about the significance or lack thereof of the test results in this case.
Jeffrey MacDonaldPolygraph expert John Reid administered a polygraph exam to MacDonald in the spring of 1970. The test results were deemed inconclusive and MacDonald told interviewer Jeffrey Elliott that the results were due to the fact that he was "frantic with worry." Several weeks later, polygraph expert Cleve Backster administered a polygraph exam to MacDonald. Backster concluded that MacDonald had flunked the exam. In 1985, polygraph expert David Raskin administered a polygraph exam to MacDonald in prison. Raskin concluded that MacDonald had passed the exam. MacDonald also refused to take a polygraph exam for the CID in 1970, and in 1973, a friend of MacDonald's approached famed attorney Vincent Bugliosi to inquire about Bugliosi representing MacDonald. One of Bugliosi's stipulations was that MacDonald take a polygraph exam. MacDonald's refusal to take a polygraph exam coupled with information gathered about the Government's case against MacDonald, resulted in Bugliosi refusing to represent MacDonald.
Helena StoeckleyIn 1971, CID polygraph expert and CID Hall of Famer Robert Brisentine administered a polygraph exam to Stoeckley. He concluded that Stoeckley believed that she was present at the crime scene, but added that the results were inconclusive due to Stoeckley's excessive drug use.
In 1980, over a two-day period, polygraph expert Scott Mero administered four separate polygraph exams. He labeled the first day of testing as Phase One and the second day of testing as Phase Two. Mero determined that Stoeckley passed Phase One, but concluded that Stoeckley flunked the exams administered in Phase Two.