My husband and I are both under investigation by the local cops and state child services after our baby had blood in the head from an accident we told the Dr.'s and cops about to begin with. We took polygraphs and I was told mine was inconclusive on the first 4 charts and I passed the last two. My husband was told he failed, he was told I failed and they are trying to pin him against the wall and are accusing him of doing something to our baby. He did not lie and we are all surprised he "failed." The polygraph is based on readings of the autonomic nervous system. He has a documented disorder of the autonomic nervous system that causes him to have eratic blood pressures and pulse rates and even pass out. Does anyone know if this would be just cause to disregard the first test? They want him to take another and he will not. We do not think he should. The cops are just trying to guilt him into admitting doing something he never did!! Way to go Portland police department. Chalk up another one for your already shady reputation...  
Our advice..DO NOT TAKE A POLY! Make the cops use actual facts and evidence to determine their course of action!

Thank you for your input. Your response has validated what we already are thinking. We are in the process of seeking counsel, and are refusing to take further tests. I will keep all posted to our outcome in the hopes that our situation will help others like us. 
Thanks again!