Actually its confirmed they did not use them. They are going out of their way not to solve this case, being more concerned of Gov't employee son JVDS, than NH.
Sometimes I think we're assuming an investigation is taking place; vs. crisis management and damage control for those in power.
Stating not only are poly tests not allowed (nor in court) but videos are not allowed in court.
SO.....even if there was a video of NH's abduction, it could not be used as evidence.