Polygraph examiners may not offer an opinion on the test subject’s guilt or innocence, a state appeals court ruled on Tuesday in granting a new trial in a robbery and assault case.

The Appellate Division in State v. Mervilus, A-5182-07, also said if prosecutors want to introduce the results of polygraph examinations, judges must first hold hearings under N.J. Rule of Evidence 104 to determine whether the tests were reliable and to develop clear records of their findings.