In 2007, Jeremy Bamber convincingly passed a lie detector test conducted by Terry Mullins, an expert in the field. Asked a series of twelve questions including “Did you shoot your family on 7 August 1985?”, “Did you hide a rifle silencer in a cupboard after shooting your family?” and “Did PC Berry radio in a report of seeing someone in an upstairs window around 4am on the morning of the shooting?”, Bamber gave answers that indicated his innocence and affirmed the sighting, and no indices of deception were apparent in the results recorded by the polygraph.
But despite its notoriety as a ruthless instrument of detection, the polygraph test has almost no credibility within the scientific community. The ability of such a device to accurately assess the truthfulness of answers is in reality little better than chance, relegating the science of polygraphy to the level of astrology and tarot cards. What’s more, the technique is particularly ineffective when applied to individuals with [ censored word]ocial/psychopathic personality disorders, tendencies which are often displayed by people who kill deliberately. Gary Ridgway, the man convicted on the basis of DNA evidence (and later his own confession) as Utah’s Green River killer, passed a polygraph with flying colours at an early stage of the investigation. Conversely, Bill Wegerle, an innocent man, failed two separate tests after coming under suspicion of the murders.
Elated after receiving the results of his 2007 polygraph test, Bamber told the Daily Mirror “I didn’t do it, I couldn’t have done it, I wouldn’t have done it.”
But he could have done it, seemingly would have done it and very probably did do it.