Herman Cain may not have to take a lie detector test because, as one investigator claims, he already did - and passed with flying colours. The sexual harassment scandal has shaken Cain’s campaign but has showed few signs of derailing it, as he spoke at Wednesday night's Republican debate to loud applause. In the face of the accusations, Cain said earlier this week that he was willing to take a lie detector test, but only 'if I have to.' Enter TJ Ward, a private investigator who claims to have a fool-proof method of separating the honest from the liars.