State v. Jones, 478 P.3d 1055

Police responded to neighbor 911s and found Victim’s apartment door forced; Victim and Jones initially spoke together and said a Chromebook was stolen the previous day.
Officer found the burglary story vague and inconsistent, then separated Victim and Jones; Victim changed her account and said Jones had forced the door and earlier put his hands around her neck.
Officer testified (without timely objection in many instances) about his training and experience interviewing domestic-violence victims and explained why he became stern with Victim; on redirect he briefly began to say he had received additional information corroborating her, but the court sustained an objection and told the jury to disregard that statement.
The court overruled a later objection to testimony about the officer’s training but repeatedly instructed the jury that credibility determinations were the jury’s sole province and no witness may testify whether another witness was truthful.
Jones moved for a mistrial based on alleged bolstering; the court denied the motion as the prejudicial remark was promptly struck and the jury instructed to disregard it.
Jury convicted Jones of aggravated assault and criminal mischief; Jones appealed claiming improper bolstering/opinion on witness truthfulness.

Issue	Jones' Argument	State's Argument	Held
Whether Officer’s testimony impermissibly bolstered Victim’s credibility or opined on truthfulness	Officer’s statements and comparisons to other victims impermissibly vouched for Victim and were inadmissible under Rule 608	Officer’s testimony described general training/experience and interview techniques, not a specific-opinion on Victim’s truthfulness; any improper statement was cured by prompt instruction	The court affirmed: testimony about training/experience was admissible and did not opine on truthfulness of Victim on a particular occasion; jury instructions cured any prejudice

State v. Adams, 5 P.3d 642 (Utah 2000) (expert testimony about a victim’s cognitive capacity did not impermissibly vouch for truthfulness)
State v. Cegers, 440 P.3d 924 (Utah Ct. App. 2019) (improper bolstering where witness opined victim was truthful)
State v. Stefaniak, 900 P.2d 1094 (Utah Ct. App. 1995) (testimony that victim ‘‘seemed to be quite candid’’ held improper bolstering)
State v. Bragg, 317 P.3d 452 (Utah Ct. App. 2013) (officer testimony that victim appeared "genuine" constituted improper bolstering)
State v. Boyle, 440 P.3d 720 (Utah Ct. App. 2019) (reversal requires reasonable likelihood that error affected verdict)
State v. Mead, 27 P.3d 1115 (Utah 2001) (to reverse for improper bolstering, defendant must show overwhelming probability jury could not follow curative instruction)