What is this mythical lie detector you speak of? No trustworthy lie detector exists. If you disagree: does yours work for all mental variations (psychopaths, autism, retardedness, ...) and physical variations (Down syndrome, a score of other genetic abnormalities, ...)? Have you actually verified the research or trust someone who did?
No lie detector exists that is effective to the standards we demand in a court of law, but that doesn't mean there isn't one effective enough for the purposes of an organized crime syndicate looking to buy votes.