Terry Mullins is peddling nothing more than a gimmick. The polygraph in its present form cannot detect the difference between lies and the truth. The contraption detects minute psysiological changes in the body as a response to being asked questions and since every single person reacts in different ways no reliable conclusion can ever be reached thus why the device is not admissable in criminal cases. If the same person were asked the same questions over the course of several days, different responses would result.
The polygraph has its uses however but not as a lie detector. You could say it is more of a conscience detector. In the Kate Prout murder case, husband Adrian was the main suspect. His then girlfriend believed him to be innocent and ran a campaign to have him freed. She was so sure that he was innocent she persuaded Prout to take the polygraph test which he failed. A short time thereafter he confessed that he had in fact strangled his wife and buried her remains on their farm. The polygraph is used as a scare tactic, nothing more and nothing less.
Jeremy Bamber passing a polygraph test means only one thing and that is that Jeremy Bamber passed a polygraph test. It has no relevance to guilt or innocence. Terry Mullins will continue to peddle his polygraph at £1000 a go but at the end of the day it is a meaningless exercise. The polygraph is a fake science, it has no place in a any criminal justice system.