Polygraph Results Are the Subject of Expert Testimony
Generally speaking, polygraph results are not admissible in Utah courts because they do not satisfy Utah Rules of Evidence 702. That is because over time, they have been unable to meet the basic threshold of being inherently reliable in the scientific community. A few cases have set forth the standard of the admissibility of polygraph tests: State v. Rimmasch, 775 P.2d 388 (Utah 1989); State v. Crosby, 927 P.2d 638 (Utah 1996); and State v. Brown, 948 P.2d 337 (Utah )1997).
In Rimmasch, the court established a three-part standard for admitting scientific evidence under Rule 702 of the Utah Rules of Evidence:
- A showing that the proposed evidence is inherently reliable. This can be done through a showing of general acceptance of the principle or technique int he relevant scientific community or by proffering a sufficient foundation to demonstrate the inherent reliability of the underlying principles and techniques.
- A showing that there is adequate foundation for the proposed testimony.
- The probative value of the proferred evidence must outweigh the danger of unfair prejudice, confusing the issues, misleading the jury, undue delay, wasting time, or needlessly presenting cumulative evidence.
The Crosby court reaffirmed the applicability of Rimmasch as the standard for determining whether lie detector evidence was admissible and admonished future proponents of polygraph evidence to make a detailed foundational showing, specifically demonstrating how research or recent developments in the field have made polygraph evidence more reliable.
Finally, the Brown court found that at that time (1997) the admission of lie detector evidence was not appropriate for judicial notice. This remains true to the present. Thus, if a proponent wishes to admit polygraph evidence he must provide the foundational showing required by Rimmasch.
To date, Utah appellate courts have not found that lie detector tests are inherently reliable, and therefore, they are not admissible as scientific evidence. That does not mean, however, that they cannot be admitted. So long as Rimmasch is satisfied, they can be, but the current state of the science behind polygraph examinations suggests that they will not be admitted for some time to come.