## Facts

- Kathy Tanner was tried in a bench trial for the death of her three-year-old daughter, Tawnya Tanner.
- Tawnya was brought to the hospital unconscious with severe brain injury, never regained consciousness, and died the next day.
- The parties stipulated to the autopsy report, which concluded death resulted from “subdural hematoma associated with multiple contusions of the body.”
- The autopsy identified numerous contusions over the child’s body and severe head trauma inconsistent with a minor incident.
- Tanner stated the injuries resulted from Tawnya falling from a slide at a park.
- The prosecution presented multiple medical experts who described the nature and pattern of injuries and testified about battered child syndrome, including that the presentation fit a pattern of non-accidental trauma.
- The trial court admitted evidence of prior injuries and alleged prior abuse of Tawnya, including an earlier hospitalization when Tawnya was an infant for multiple fractures that Tanner attributed to a fall.
- Tanner’s partner testified Tanner was extreme in disciplining Tawnya, including throwing her against walls and kicking her, and reported hearing loud impacts on the day Tawnya was found unconscious.
- Tanner was convicted of manslaughter and sentenced to an indeterminate term of one to fifteen years’ imprisonment.

## Issues

1. Whether the evidence was sufficient to prove manslaughter beyond a reasonable doubt.
2. Whether expert testimony on battered child syndrome was admissible.
3. Whether evidence of prior injuries and prior acts toward the same child was admissible or impermissible propensity evidence.
4. Whether other evidentiary rulings, including exclusion of polygraph-related matters, required reversal.

## Decision

- The Utah Supreme Court affirmed the manslaughter conviction.
- The court held the circumstantial and expert evidence, together with evidence of prior injuries and conduct toward the child, was sufficient for the factfinder to find guilt beyond a reasonable doubt.
- The court upheld admission of battered-child-syndrome testimony as relevant expert evidence assisting the trier of fact in evaluating whether injuries were accidental or inflicted, without deciding the defendant’s legal guilt.
- The court upheld admission of prior-acts and prior-injury evidence as probative of a pattern of abuse toward the same child and of absence of accident, not merely character or propensity.
- The court found no reversible error in the remaining evidentiary rulings, including matters related to polygraph evidence, and no abuse of discretion or prejudice warranting relief.

## Legal Principles

- Appellate review of evidentiary weight and credibility is limited; a conviction may rest on circumstantial evidence if it permits a rational factfinder to find guilt beyond a reasonable doubt.
- Expert testimony is admissible when it helps the trier of fact understand medical evidence and evaluate whether injuries are consistent with accidental versus non-accidental causes; battered-child-syndrome testimony may be used for this purpose.
- Expert testimony that describes medical patterns and probable causes does not improperly decide the ultimate legal issue when the factfinder retains responsibility for determining culpability.
- In child-abuse prosecutions, evidence of specific prior instances of the defendant’s treatment of the same child may be admitted to show a specific pattern of conduct and to prove matters such as intent and absence of mistake or accident, rather than general propensity.
- Trial courts have broad discretion over admission and exclusion of evidence; reversal requires a showing of abuse of discretion and resulting prejudice, and polygraph-related evidence is generally disfavored.

## Conclusion

The Utah Supreme Court affirmed Tanner’s manslaughter conviction, holding that the medical evidence and history supported a finding of non-accidental trauma and that the trial court properly admitted battered-child-syndrome expert testimony and prior-treatment evidence to show a pattern of abuse and negate accident.


State v. Tanner, 675 P.2d 539 (Utah 1983)