William Gerard Palmer v. State, 05-14-00671-CR

William Gerard Palmer was convicted by a jury of capital murder for the stabbing deaths of his in‑laws, Mary and Ray Davis, and sentenced to life imprisonment without parole.
Facts: Palmer’s marriage to Donya Palmer had deteriorated; Donya had left briefly and returned; early morning the next day Palmer attacked and fatally stabbed Mary and Ray at the Davis house; a child hid and called 911; Palmer was later arrested and photographed with injuries and blood on his fingers.
Defense theory: Palmer suffered from chronic mental illness (depression, ADHD, anxiety), recent changes in psychotropic medications, impulsivity, and a possible religious/delusional belief that his wife was demon‑possessed; defense sought to introduce expert testimony from Dr. Kristi Compton to show diminished capacity/mental state at the time of the killings.
Trial rulings: The trial court excluded Dr. Compton’s proffered testimony after a sub rosa hearing because she could not state an opinion whether Palmer had the specific intent required for capital murder and her testimony risked confusing the jury.
Charge issue: Defense requested lesser‑included instructions (voluntary manslaughter, negligent homicide); the court declined to submit any lesser‑included offenses. Appellant appealed, arguing erroneous exclusion of expert testimony and entitlement to a manslaughter instruction.

Issue	Plaintiff's Argument (State)	Defendant's Argument (Palmer)	Held
1–2. Exclusion of Dr. Kristi Compton’s testimony on diminished capacity/intent	Exclusion proper because Compton could not form/express an opinion whether Palmer had the requisite intent; her testimony would not assist the jury, risked confusion/prejudice, and duplicated other evidence	Compton would provide evidence negating mens rea and support diminished‑capacity defense	Court upheld exclusion (trial court within discretion); alternatively any error harmless because other experts testified and the proffer was weak
3. Request for manslaughter (lesser‑included) instruction	No reversible error: even if manslaughter is a lesser‑included offense, no affirmative evidence showed Palmer acted only recklessly rather than intentionally/knowingly	Manslaughter instruction necessary because expert testimony and other evidence supported lack of intent, creating a rational basis for manslaughter	Court held appellant not entitled to manslaughter instruction; preserved‑error argument weak; no evidence directly germane to recklessness
State cross‑point: Modify judgment to reflect sentence accurately	N/A (State requests correction)	N/A (appellant did not dispute clerical error)	Judgment to be modified/reformed to state life without parole (correct the clerical error)

Crane v. Kentucky, 476 U.S. 683 (U.S. 1986) (defendant’s right to present a meaningful defense balanced against trial court’s gatekeeping authority)
Montgomery v. State, 810 S.W.2d 372 (Tex. Crim. App. 1990) (factors for relevancy and probative value in evidentiary balancing)
Jackson v. State, 160 S.W.3d 568 (Tex. Crim. App. 2005) (diminished‑capacity evidence must negate the culpable mental state)
Cavazos v. State, 382 S.W.3d 377 (Tex. Crim. App. 2012) (standards for submitting lesser‑included offenses; evidence must be directly germane)
Rice v. State, 333 S.W.3d 140 (Tex. Crim. App. 2011) (two‑step test for lesser‑included offense instructions)
Mays v. State, 318 S.W.3d 368 (Tex. Crim. App. 2010) (distinguishing admissible diminished‑capacity evidence from unhelpful general mental‑health evidence)
Almanza v. State, 686 S.W.2d 157 (Tex. Crim. App. 1985) (harm analysis for jury‑charge error)
King v. State, 953 S.W.2d 266 (Tex. Crim. App. 1997) (definition of substantial right and harmless‑error standard)