## Facts

- The State of Utah charged Robert Michael Sheehan with aggravated assault and burglary based on an incident at a residence.
- The State’s case linking Sheehan to the location rested on latent fingerprint evidence; there was no eyewitness identification tying him to the scene.
- The prosecution presented fingerprint-identification evidence to show Sheehan was present at, or connected to, the residence involved in the alleged crimes.
- Sheehan sought to present testimony from a defense witness who would challenge the accuracy of fingerprint identification technology and the reliability of fingerprint matching as used in criminal cases.
- The trial court excluded the defense’s proposed testimony under Utah Rule of Evidence 702, reasoning that existing Utah decisions treated fingerprint identification evidence as sufficiently reliable to satisfy Rule 702’s threshold for admissibility.
- A jury found Sheehan guilty, and he appealed to the Utah Court of Appeals, arguing the exclusion of the defense witness was erroneous given the central role fingerprint evidence played at trial.

## Issues

1. Whether the trial court erred under Utah Rule of Evidence 702 by excluding the defense’s proposed testimony challenging the accuracy and reliability of fingerprint identification technology.
2. Whether the exclusion improperly limited Sheehan’s ability to contest the State’s primary proof connecting him to the crime scene.
3. Whether Utah precedent recognizing fingerprint evidence as sufficiently reliable for admissibility permitted the trial court to bar generalized reliability attacks offered through a defense witness.

## Decision

- The Utah Court of Appeals affirmed Sheehan’s convictions.
- The court held the trial court did not abuse its discretion under Utah Rule of Evidence 702 in excluding the defense’s proposed testimony aimed at attacking fingerprint-identification reliability at a general level.
- The court accepted the trial court’s reliance on Utah case law treating fingerprint identification evidence as meeting Rule 702’s baseline reliability requirement.
- The court concluded that limiting the proposed testimony did not amount to reversible error where the defense still had other tools available to challenge the State’s fingerprint evidence at trial (such as cross-examination and argument about the evidence presented).

## Legal Principles

- Utah Rule of Evidence 702 requires that opinion testimony based on specialized knowledge be sufficiently reliable and helpful to the factfinder, with the trial court serving as the gatekeeper.
- When prior Utah decisions treat a category of proof—such as fingerprint identification—as reliable enough to satisfy Rule 702’s threshold for admissibility, a trial court may exclude testimony offered primarily to attack the discipline’s general validity rather than the application in the case.
- A defendant’s ability to present a defense is subject to ordinary evidentiary limits; excluding evidence under Rule 702 does not, by itself, establish a constitutional violation if the defendant retains meaningful ways to test the State’s proof.

## Conclusion

In State v. Commissioner, the Utah Court of Appeals affirmed Sheehan’s aggravated-assault and burglary convictions, holding the trial court acted within its discretion under Utah Rule of Evidence 702 when it barred the defense’s proposed testimony challenging fingerprint-identification accuracy, given Utah authority treating fingerprint evidence as sufficiently reliable for admissibility and the availability of other methods to contest the State’s fingerprint proof.


State v. Commissioner, 273 P.3d 417 (2012)