In pre-trial arguments for State v. Byron Case, it was agreed that neither side would go into the fact that Kelly Moffett had taken a VSA (Voice Stress Analysis) test;¹ however, Kelly Moffett inadvertently mentioned it during her direct examination.²

Upon objection by defense counsel, several minutes of discussion were held outside the hearing of the jury, and some private discussion was held by Case and his counsel. At the end of those discussions, it was decided that there would be no mistrial,³ and that the judge would give a "cautionary instruction" to the jury. His instruction went as follows:

Ladies and gentlemen, I have an instruction I would like to give to you, and I would like you to listen to what I have to say very carefully, if you would.

There is no witness in this case that has ever taken any test with conclusive results regarding their truthfulness or untruthfulness.

Furthermore, such tests are deemed inadmissible and incompetent as evidence in state and federal courts throughout this country.

To consider any such evidence in this case for or against either side would be horribly unfair. For that reason, you should disregard any testimony regarding such evidence.⁴

In truth, the fact of Kelly having taken a VSA could have been dangerous for both sides, and both defense and prosecution had reasons to avoid discussion of it.

In his 29.15 appeal, Byron Case tesitfied that

[A]fter trial counsel objected to Moffett's testimony about the lie detector test, he and trial counsel went into a room outside of the courtroom to talk about the issue; that he told trial counsel that he wanted a mistrial. He told the Court that trial counsel was concerned about the witnesses' availability for the second trial; and that trial counsel never inquired of the witnesses to know whether they could return for another trial.<

Case's counsel, Horton Lance, testified that

[H]e and his client discussed various concerns they had regarding the availability of witnesses, future trial dates and Case's desire to move forward with the case as soon as possible because he was in custody with a high bond; and that both he and Case discussed all the available options and decided together not to request a mistrial.

The Jackson County Circuit Court denied Case's appeal,⁵ as did both the Appellate and Missouri Supreme Courts.⁶

It could be inferred that Byron Case, believing that he was going to win acquittal, and wishing to not delay what he considered an inevitability, himself chose (or at the very least, agreed with his counsel) to forego being granted a mistrial.