State v. Walker, 391 P.3d 380

Timothy Walker choked his wife in a hotel room; son witnessed wife lose consciousness after approximately 10–15 seconds of pressure to her neck. Wife later regained consciousness and declined immediate hospitalization; later medical exam showed soreness and red marks but no long-term complications reported.
Walker was charged with aggravated assault (second-degree felony). He elected jury trial and presented expert testimony that brief carotid-pressure-induced unconsciousness can quickly reverse and may not cause structural neck injury.
The trial court instructed the jury on statutory definitions of assault and serious bodily injury and, over Walker’s objection, gave Instruction 18: "Strangulation to the point of unconsciousness constitutes serious bodily injury."
Prosecutor emphasized Instruction 18 in closing; the jury asked for the meaning of "constitutes" as used in Instruction 18 during deliberations.
The jury acquitted on the greatest charge but convicted Walker of aggravated assault (third-degree felony). Walker appealed, arguing the instruction deprived him of his federal Sixth and Fourteenth Amendment jury-trial rights.
The Court of Appeals held the instruction unconstitutionally removed from the jury the question whether the facts established the element of serious bodily injury, vacated the conviction, and remanded for a new trial.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether instructing the jury that "strangulation to the point of unconsciousness constitutes serious bodily injury" violated the Sixth and Fourteenth Amendment right to a jury trial	State: Utah Supreme Court precedent supports treating strangulation-to-unconsciousness as serious bodily injury as a legal matter, so instruction was proper	Walker: The instruction usurped the jury’s fact-finding role and relieved the State of proving an element beyond a reasonable doubt	Court: Instruction was improper because it foreclosed independent jury consideration of the element; conviction vacated and remanded

State v. Fisher, 680 P.2d 35 (Utah 1984) (discussed sufficiency of evidence where defendant intended to cause unconsciousness; court observed strangulation can constitute serious bodily injury under facts presented)
State v. Speer, 750 P.2d 186 (Utah 1988) (addressed whether evidence left a rational basis for lesser-offense instructions where choking nearly caused unconsciousness)
Carella v. California, 491 U.S. 263 (1989) (holding mandatory presumptions in jury instructions can violate due process by relieving prosecution of burden of proof)
United States v. Gaudin, 515 U.S. 506 (1995) (judge may instruct on law but jury must find facts establishing elements beyond a reasonable doubt)
Sullivan v. Louisiana, 508 U.S. 275 (1993) (conviction must rest on jury finding beyond a reasonable doubt of every element)