Dumas v. State, 428 P.3d 449

Darren Dumas and wife (Ms. Dumas) married in 2015; relationship deteriorated and in September 2016 multiple altercations occurred, including alleged choking/strangulation and other physical abuse.
Ms. Dumas sought help from the Hope Agency; staff observed injuries, transported her to the hospital where petechiae and bruises were noted.
Dumas was charged with strangulation of a household member and domestic battery, convicted on both counts, and appealed.
On appeal Dumas challenged three evidentiary matters he did not object to at trial: (1) testimony about post‑incident assistance provided by the Hope Agency (victim impact evidence); (2) a witness’s statement that she had never seen a false report (argued as opinion of guilt); and (3) the same testimony as improper vouching for the victim’s credibility.
The defense trial strategy emphasized undermining the victim’s credibility by suggesting she fabricated the report to obtain Hope Agency benefits; defense counsel elicited and relied on Hope Agency testimony during trial and closing.
Appellate review applied the plain‑error standard because no contemporaneous objections were made.

Issue	Plaintiff's Argument (Dumas)	Defendant's Argument (State)	Held
Admission of victim‑impact evidence (testimony that Hope Agency paid housing, food, rent, etc.)	Testimony about agency assistance was irrelevant victim‑impact evidence intended to inflame the jury and should have been excluded.	Evidence was relevant to credibility because defense attacked victim’s motive to fabricate; testimony also clarified prior testimony and was not inflammatory.	No plain error: testimony was relevant to credibility given defense theory and not unduly inflammatory.
Opinion of guilt (witness said she had never seen a report that didn’t turn out to be true; “no reason to believe incidents weren’t as reported”)	That testimony constituted an impermissible opinion that Dumas was guilty.	The statement did not reach an actual conclusion of guilt; it merely expressed no reason to disbelieve the victim.	No plain error: statement did not state an actual conclusion of defendant’s guilt.
Vouching for victim credibility (same testimony)	The testimony improperly vouched for the victim and invaded the jury’s role to assess credibility.	In context, the testimony was brief, largely cumulative of prior testimony elicited by defense, and invited by defense strategy; no prejudice shown.	No plain error: brief/cumulative, defense had emphasized same points, and no reasonable probability of a different outcome.

Carroll v. State, 352 P.3d 251 (Wyo. 2015) (plain‑error standard for unpreserved evidentiary claims)
Schreibvogel v. State, 228 P.3d 874 (Wyo. 2010) (victim impact evidence admissibility turns on relevance)
Ogden v. State, 34 P.3d 271 (Wyo. 2001) (prosecution may not elicit opinion testimony on defendant’s guilt or vouch for witness credibility)
Evenson v. State, 177 P.3d 819 (Wyo. 2008) (distinguishing statements that someone was "responsible" from an explicit opinion of guilt)
Bennett v. State, 794 P.2d 879 (Wyo. 1990) (examples of improper opinion testimony by investigating officers)