Dung Ngoc Thi-Zeluff v. State, 10-18-00171-CR

Defendant Dung Ngoc Thi‑Zeluff was convicted of capital murder for killing her five‑month‑old daughter; she appealed on the ground that the jury’s rejection of her insanity defense was factually insufficient.
On Halloween 2016 Dung locked a bedroom, strangled the infant, and thereafter sat with the body; she admitted the act and described it as “evil.”
Law‑enforcement and family witnesses observed Dung coherent, communicative, and capable of planning (locking the door, waiting until the father left); she asked about penalty and bond during a post‑offense interview.
CPS records and family testimony established prior suicidal and homicidal threats, prior psychiatric hospitalizations (2010 and 2016), medication for Parkinsonian symptoms and depression, and periods off medication while breastfeeding.
Defense experts (psychiatrist Dr. Cantu and psychologist Dr. Carter) diagnosed severe mental illness and borderline personality disorder; Dr. Cantu opined possible psychosis/delusions and inability to appreciate moral wrongfulness, but conceded records did not show hallucinations and that Dung knew killing was criminally wrong; Dr. Carter concluded Dung was sane and planned the killing.
The jury rejected the insanity defense; the Tenth Court of Appeals affirmed, finding the evidence supporting sanity and the circumstantial evidence of planning sufficient so that the verdict was not ‘‘manifestly unjust.’'

Issue	Dung's Argument	State's Argument	Held
Factual sufficiency of jury’s rejection of insanity defense	Expert and lay evidence show severe mental disease/defect (postpartum depression/psychosis, Parkinsonian effects, medication side effects) such that Dung did not know killing was wrong	Circumstantial and testimonial evidence (locking door, waiting until father left, admitting criminal wrongness, asking about penalty/bond, removing rings) show Dung knew conduct was wrong and acted intentionally	Affirmed — the jury’s rejection of insanity was not against the great weight and preponderance of the evidence

Matlock v. State, 392 S.W.3d 662 (Tex. Crim. App. 2013) (standard for factual‑sufficiency review of affirmative defenses)
McAfee v. State, 467 S.W.3d 622 (Tex. App.—Houston [1st Dist.] 2015) (adopts civil preponderance standard and outlines review for insanity affirmative defense)
Meraz v. State, 785 S.W.2d 146 (Tex. Crim. App. 1990) (burden of proof for affirmative defenses)
Ruffin v. State, 270 S.W.3d 586 (Tex. Crim. App. 2008) (defines ‘‘wrong’’ as ‘‘illegal’’ for insanity defense)
Bigby v. State, 892 S.W.2d 864 (Tex. Crim. App. 1994) (insanity involves legal and ethical considerations; jury’s province)
Graham v. State, 566 S.W.2d 941 (Tex. Crim. App. 1978) (circumstances of the crime matter; jurors may weigh expert testimony)
Torres v. State, 976 S.W.2d 345 (Tex. App.—Corpus Christi 1998) (jury may consider circumstantial evidence such as attempts to conceal or expressions of regret)