Kelly Moffett was interviewed on August 22, 1998 by Jackson County Sheriff's Deputy Gary Kilgore in relation to the murder of Anastasia WitbolsFeugen. During the course of that interview, Kilgore administered a Voice Stress Analysis (VSA) test on Kelly. The test itself was found to be defective, and whether she passed or failed is unknown.

Standard polygraph tests (colloquially called "lie-detector" tests) have long been considered notoriously unreliable, and their results are not admissible in court. VSA tests are even more unreliable than polygraph tests,¹ and are generally employed by police only for an attempted psychological advantage against unsophisticated or easily intimidated witnesses. There are many effective methods to beat a voice stress test, methods readily available on the internet and local library, all available to both Case and Moffett at the time.

At the time Kelly Moffett was engaging in this interview, Byron Case was categorically refusing to even speak with police, much less submit to any tests. His stated reason for his nearly complete lack of cooperation with investigators has been the standard "advice from his lawyer", though attorneys usually have reasons to give such advice, and Case has never stated his attorney's grounds for such reservations.

During pre-trial motions, it was agreed by both sides that no mention of the VSA would be made during trial.² However, Kelly Moffett inadvertently mentioned the VSA she was given during her direct testimony.³ Byron Case and his attorney were given the option of requesting a mistrial, and they declined the offer.⁴

Jurors were instructed to disregard the mention of the test, and were clearly informed that the test was wholly unreliable.⁵ Since that time, Case and his supporters have focused on two contradictary assertions. First, they have argued that the fact that Kelly Moffett even submitted to a VSA test, arguing that it showed that she must have believed in what she said, no matter how the test came out. Second, they have argued that her having inadvertently mentioned the VSA in her trial testimony prejudiced the jury into believing that she passed the test when accusing Byron Case of murder.

No matter what they believe, the truth is that the VSA was of little to no value legally.

First, as we stated before, the VSA test is an unsophisticated and unreliable test, more unreliable than the standard polygraph; it is primarily used by police for psychological advantage, and methods for beating it are easy to find.

Second, the VSA is inadmissible in court. Case and Moffett had nothing to lose by her having taken it; had she passed, she and Case could have used it to get police off their backs; had she failed, she could have fallen back on the test's unreliability. This was a win-win situation for Case; the only surprise is that he didn't take it himself, especially when he was interviewed under limited immunity.⁶