Steven Aftergood of the Federation of American Scientists’ Project on Government Secrecy comments in his Secrecy News e-mail publication:
A REJOINDER ON POLYGRAPH
It is not correct to say that no spy has ever been caught as a result of polygraph testing.
John F. Sullivan, who served as a CIA polygrapher for 31 years, wrote to set the record straight, noting that the polygraph played a role in the identification of spies such as Sharon Scranage and James Nicholson.
See his “Rejoinder on Polygraph” here:
http://www.fas.org/sgp/eprint/sullivan.html
Mr. Sullivan is not an uncritical proponent of polygraph testing. Nor does he insist, against the findings of the National Academy of Sciences and others, that the polygraph is scientifically valid in the way that other diagnostic tools are.
“I have always believed that trying to sell polygraph as a science was a mistake, and as I stated in my book, polygraph is 92% art and 8% science,” he told Secrecy News.
“There are Rembrandts and finger painters among polygraph examiners, and when done by a ‘Rembrandt,’ polygraph is very effective,” he wrote in an email. “When done by a finger painter, polygraph is ineffective, often abusive, and can be dangerous.”
This is a striking analogy since it places the emphasis on the intuitive gifts of the examiner rather than on the technique or technology of the test. One can study and teach painting, but no training program can reliably produce “Rembrandts” at will.