Historically, the courts in this country have consistently rejected the use of polygraph test results in the prosecution of criminal cases. This judicial philosophy is grounded upon a well-recognized  principle that says, in essence, that the polygraph machine is just not reliable enough.

Over two decades ago, New Jersey’s Supreme Court concluded that, notwithstanding the polygraph’s lack of reliability, results from a polygraph test can be put into evidence in a criminal prosecution if both and the defendant, with counsel, and the government agree. That principle of law was reaffirmed approximately 2 years ago.

In a case decided by the Appellate Division last week, the court concluded that despite a stipulation authorizing the admissibility of a polygraph test, the government still had a responsibility to establish that the test were reliable.

In addition, the court castigated a government polygraph expert who sought to convince the jury that the polygraph process was unassailable and entirely capable of determining people who were “guilty or innocent” or “truthful or lying.” On this issue, the Appellate Division noted that although an expert in a criminal case may offer an opinion as to whether a defendant committed the crime, that expert cannot offer an opinion as to defendant’s “guilt” because that type of testimony truly invades the prerogative of the jury.