State v. Isbell, 524 S.W.3d 90

On Sept. 19, 2014, a 17-year-old student (Victim) and Defendant (her step‑father) argued at home; Victim, agitated, pulled hair, bit her arm and kicked Defendant in the shin.
Defendant struck Victim in the face, causing a bloody nose; Victim fled to a relative’s house.
Defendant was charged with one count of child abuse (Mo. Rev. Stat. § 568.060) and tried by jury; he did not request a self‑defense instruction at trial.
The trial court gave a requested instruction on reasonable discipline of a minor but did not, sua sponte, give a self‑defense instruction.
Defendant argued on appeal the court plainly erred by failing to submit a self‑defense instruction; the court reviewed under plain‑error standard and affirmed conviction.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the trial court plainly erred by failing to submit a self‑defense instruction sua sponte.	State: No plain error because Defendant failed to inject substantial evidence supporting self‑defense.	Isbell: Trial court should have given a self‑defense instruction despite no request, because facts (Victim’s agitation and kicking) supported it.	Court: No plain error — Defendant did not introduce substantial evidence a reasonable person would have believed force was necessary, so no instruction was required.

State v. Westfall, 75 S.W.3d 278 (Mo. banc 2002) (self‑defense instruction required only when substantial evidence supports it)
State v. Avery, 120 S.W.3d 196 (Mo. banc 2003) (definition of "substantial evidence")
Jones v. State, 495 S.W.3d 789 (Mo. App. E.D. 2016) (defendant must inject issue of self‑defense into the evidence)
State v. Powers, 913 S.W.2d 138 (Mo. App. W.D. 1996) (view evidence in light most favorable to asserted self‑defense theory when evaluating instruction)
Hendrix v. State, 369 S.W.3d 93 (Mo. App. W.D. 2012) (reasonableness of belief tested objectively)
State v. Miller, 372 S.W.3d 455 (Mo. banc 2012) (plain‑error review of instructional issues)