As a criminal trial lawyer in Newark, NJ, located in Essex County NJ, I see a lot of criminal cases. Essex County holds the dubious distinction of having the most criminal cases of any County in New Jersey. Over the years, I have had a number of clients who wanted to 'prove' they were innocent by taking a polygraph. My response has always been, NO. Although a recent article touts ways to 'beat a polygraph', there are less risky ways to avoid a conviction, or beat the State's case.
Under NJ evidentiary rules, a polygraph is not admissible as evidence, unless the defense and the State stipulate that it is admissible. No prosecutor in their right mind will agree to consider a polygraph as establishing the innocence of a defendant, unless the State knows that the defendant is agreeing to let the polygraph be used against them if the defendant fails the polygraph. I have had clients who I truly believed were innocent, take a polygraph and fail it. That did not make them guilty in my eyes; it simply meant that this test was not accurate enough to bet your future and your freedom on. The above referenced article is yet another reason to discount this type of test as not being a good defense tool.
If you are arrested, exercise your right to counsel and retain an experienced criminal trial lawyer; and, exercise your right to remain silent and make the State prove your guilt beyond a reasonable doubt. Do not add to the strength of the State case by stipulating the results of a polygraph. Not even the practice of taking a pre-test (a polygraph test done by a defense polygraphist with the results only given to the defense) before the State administers the stipulated polygraph, is worth the risk, as I have had clients who insisted on giving a stipulated polygraph, who passed the pre-test, and failed the stipulated polygraph.