Admissibility of Polygraph Test Results in Colorado

In Frye v. United States (1923), the court established the "general acceptance" standard for admitting scientific evidence. This was significantly revised in 1993 when the U.S. Supreme Court issued its landmark decision in Daubert v. Merrell Dow Pharmaceuticals, Inc. (509 U.S. 579), which introduced a more flexible and rigorous framework for evaluating expert testimony. This shift directly impacts the admissibility of evidence derived from psychophysiological veracity (PV) examinations using the polygraph.

While federal courts apply the Daubert standard, Colorado courts have adopted a more cautious approach. Under Colorado Rules of Evidence 702 and 403, polygraph results are generally inadmissible due to concerns about reliability and the potential to unfairly influence juries.

. Courts have ruled that physiological responses measured during polygraph tests can vary widely among individuals and may not reliably indicate truthfulness. As a result, polygraph evidence is typically excluded unlessboth parties stipulate to its admission, which is rare.

All that said, there have been several instances where polygraph results have been introduced and testified to in Colorado courts. These cases are typically exceptions, often involving pre-trial agreements, stipulations by both parties, or use in non-trial contexts such as plea negotiations, sentencing hearings, or parole decisions.

Judges retain discretion to admit such evidence when it is deemed relevant and not unduly prejudicial.

To meet admissibility standards under Daubert, the following criteria must be addressed:

• The PV technique must be scientifically testable.

• Its validity and reliability should be demonstrable.

• The potential error rate must be known.

• The method should be subject to peer review and publication.

• Standards governing its application must be maintained.

• It should have acceptance within a relevant scientific community.

• The examination must be properly conducted.

• The examiner must be appropriately trained and qualified.

• The entire examination should be recorded—preferably on video, or at minimum, audio.

For attorneys in Colorado, introducing PV evidence is not guaranteed but may be possible in non-trial contexts or with proper stipulations. In these settings, polygraph results may be used to support credibility or clarify disputed facts.

A recommended resource for attorneys preparing expert testimony is James Allan Matte’s Examination and Cross-Examination of Experts in Forensic Psychophysiology Using the Polygraph, which includes model transcripts and foundational guidance. It is available at Amazon.

PV examinations can be applied across a wide range of legal contexts—both civil and criminal—where factual disputes arise. Common areas of use include:

• Plea bargaining

• Motions to suppress

• Settlements

• Sentencing

• Supporting evidence

• Parole and probation

• Arbitration

• Civil actions