Commonwealth v. Anestal, 463 Mass. 655

Defendant was convicted in Superior Court of first-degree murder by deliberate premeditation for the 2003 stabbing death of her live-in boyfriend, Petitry.
Prior to the stabbing, DSS had removed the defendant’s children from their home; details of the sandal incident were contested and later contested as prejudicial.
The defense argued PTSD with depression and dissociative symptoms rendered lack of criminal responsibility at the time of the stabbing.
Expert and prosecution witnesses offered competing opinions on criminal responsibility, PTSD, and dissociative states, with a hospital-competency exam conducted after the incident.
The Commonwealth sought to admit details of prior acts of abuse against the defendant’s son to support expert opinions and to counter the defense narrative of victimhood.
The judge admitted the prior acts evidence over objections on multiple occasions, and did not provide the requested excessive-force self-defense instruction.
The trial court permitted cross-examination and testimony that drew heavily on prior bad acts without adequate limiting instructions, contributing to prejudice.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether admission of prior bad act evidence was prejudicial	McCowen: prior acts admissible for specific purposes outweigh prejudice.	Jaime/Magraw: unfair prejudice outweighs probative value; details should be excluded.	Palpable error; prejudice warranted reversal.
Whether the trial court erred by not instructing on excessive self-defense	23F allows consideration of abuse history to assess reasonableness.	Evidence supports instruction; deadly-force allowed with reasonable fear.	Instruction required; failure to give it requires reversal.
Whether the instructions on reasonable provocation properly reflected abuse history	Provocation/abuse history should be considered to support voluntary manslaughter theories.	Abuse history already admitted to support PTSD and lack of capacity; provocation instructions adequate.	Court allowed proper consideration of abuse history; not decisive to outcome.
Whether denial of a new-trial motion based on prosecutorial misconduct/ineffective assistance was proper	Excessive admission and door-opening issues taint verdict; new trial warranted.	New trial must be granted due to prejudicial error and ineffective assistance claims.	Remand for new trial due to prejudicial errors.

Commonwealth v. McCowen, 458 Mass. 461 (Mass. 2010) (prior bad acts admissible for limited purposes; palpable error standard)
Commonwealth v. Helfant, 398 Mass. 214 (Mass. 1986) (limits on prior bad act evidence for propensity; admissible for some purposes)
Commonwealth v. Magraw, 426 Mass. 589 (Mass. 1998) (limits on using expert testimony; relevance to underlying data)
Commonwealth v. Colleran, 452 Mass. 417 (Mass. 2008) (cross-examination of expert for prior acts; reliability concerns)
Commonwealth v. Pikul, 400 Mass. 550 (Mass. 1987) (foundational basis for expert testimony and data)