In Utah, scientific evidence can be admitted in a case if it satisfies a four prong test: necessity, reliability, understandability, and importance. The Utah Supreme Court set forth the test for each of these factors in State v. Rimmasch, 775 P.2d 388 (Utah 1989).
Necessity – The thing a court must address is whether there is any necessity at all for the jury to hear the evidence, and if so, how much of a necessity. This is determined by finding whether the testimony will add to the jurors’ knowledge of the case. The court also listed four inquiries that must be made to determine necessity: (1) Whether there isa close “fit” between the facts of the case and the scientific testimony; (2) What is the level of jury insight on the issue at hand? Is there substantial difference between the leval of insight offered by the expert and the level of insight the court believes the jury is likely to have? (3) Has the opponent attempted to highlight “weaknesses” in the opposition’s case? If so, expert testimony may serve to explain away the weaknesses pointed out; and, (4) Are there less objectionable forms of testimony that exist?
Reliability – The Utah Supreme Court points to two factors to determine reliability of scientific testimony. Specifically, accuracy and consistency. Courts must answer three questions in their reliability analysis: (1) Is the expert witness qualified to offer the scientific testimony? (2) Does the scientific community accept the accuracy of the evidence? (3) The more general the testimony, the more reliable it may be considered.
Understandability – The court must decide whether the evidence will be understood by the jury. Three questions apply: (1) How far removed from the jury’s common experience is the evidence? (2) Does the opposing party have his own experts who can counter the proposed expert’s scientific testimony? (3) Will the evidence overwhelm the jury?
Importance – For this prong of the test the court must determine how crucial to the resolution of the case is the scientific evidence. The more likely the evidence is to persuade the jury to decide the case one way or the other the more important it is considered to the case.
Thus, anytime it is proposed that scientific evidence be admitted to the jury, the party wanted to produce such evidence will first have to satisfy the above factors as set forth by Rimmasch.