The polygraph "discussion" drove me nuts. A polygraph relies on subjective interpretation by the operator. There is no green light that lights on a true answer or red light that lights on a lie. Instead, there is a graph drawn on a tape that has to be interpreted by the operator, based on his knowledge, skill, training, and experience. Most important, his personal beliefs, life experiences, and prejudices always have the potential to shade his interpretation.
Good polygraph operators do their best to put these personal factors aside in interpreting the results. Kind of like a judge putting his personal beliefs aside and trying his best to decide a case just on the law and the facts.
The point is that every polygraph operator's human factors are always a legitimate question. Police polygraph operators are police officers. They are hired and paid by the police, and that is where their loyalties inevitably tilt. They bring a certain outlook to the table. A "civilian" polygraph operator hired by a suspect is subject to the same legitimate concerns.
There are honest polygraphers and whores. There are skilled polygraphers and hacks. But, to say, as K & C did, that a police polygrapher is automatically more credible than one hired by the suspect is complete nonsense. Just because he's a cop doesn't make him good or objective. Just because he's hired by a suspect doesn't make him bad or biased.
For these reasons and others, polygraph results are not admissible as evidence in most courts. Prosecutors and defense attorneys use them as decision making aids. A prosecutor may decide not to charge someone if the polygraph indicates truthfulness, or vice versa. A defense attorney may decide to have his client plead instead of go to trial if the polygraph indicates deceptiveness, or vice versa.
That's all they are good for.
EDIT: A caller and an earlier poster to this thread said that a prosecution polygraph saying that Allen is thruthful would have to be given to his lawyers. This may be true, but they still couldn't use it as evidence in court, so it doesn't make any difference.
Last edited by Pintman; 02-12-2014 at 08:54 AM.
Reason: clarity
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