Commonwealth v. Williams, 619 Pa. 219

Background

Appellee was convicted of first-degree murder and abuse of a corpse for killing his wife and received a death sentence after a penalty-phase verdict finding one aggravator outweighed two mitigators.
Post-sentence, appellee filed a PCRA petition alleging he is mentally retarded under Atkins v. Virginia and Miller; the PCRA court held an evidentiary hearing focused on that claim and vacated the death sentence, imposing life imprisonment.
Commonwealth appealed, arguing the record contains abundant evidence of appellee’s adaptive functioning deficits and that he does not meet the Atkins/Miller definition of mental retardation.
The Pennsylvania Supreme Court reviews the PCRA court’s determination under a mixed question standard: factual findings supported by substantial evidence and legal conclusions not clearly erroneous.
Seven appellee experts and two Commonwealth experts testified; the PCRA court found appellee’s IQ between 70 and 75 and significant adaptive deficits present before age 18, satisfying Miller’s three-prong test for mental retardation.
The Commonwealth asserted the court erred in relying on childhood IQ scores and in weighing adaptive-deficit evidence; the court’s credibility determinations and the weight given to expert testimony were upheld on collateral review.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Is the PCRA court’s finding of mental retardation supported by substantial evidence?	Commonwealth argues evidence shows no significant adaptive deficits and appellee is not mentally retarded.	Appellee's experts credibly establish limited intellectual functioning and significant adaptive deficits present before age 18.	Yes; finding supported by substantial evidence.
Are the childhood IQ scores reliable for Miller prong three?	Childhood tests are unreliable, not comparable, biased, and should be excluded.	Childhood scores are valid evidence under Miller and remaining records show retardation.	Childhood IQ scores properly considered.
Did appellee demonstrate significant adaptive deficits under Miller’s prong two?	Commonwealth contends adaptive deficits were not substantial or pervasive.	Multiple experts document deficits across DSM-IV/AAMR domains and lay witnesses corroborate functional impairments.	Yes; significant adaptive deficits established by preponderance of the evidence.
Did Miller’s third prong (onset before 18) occur prior to 18 for appellee?	Some expert testimony disputes early onset; reliability of childhood data contested.	Evidence shows impairments and testing consistently indicate onset before 18.	Yes; onset before age 18 established by the record.
Did the PCRA court properly credit appellee’s experts over the Commonwealth’s experts?	PCRA court erred in weighting Commonwealth’s credentials over appellee’s credibility.	PCRA court’s credibility determinations are binding if supported by substantial evidence.	Yes; credibility and weight properly assigned to appellee’s experts.

Key Cases Cited

Atkins v. Virginia, 536 U.S. 304 (U.S. 2002) ( condemns execution of mentally retarded; framework adopted in Miller)
Commonwealth v. Miller, 888 A.2d 624 (Pa. 2005) (test for mental retardation under DSM-IV/AAMR; Miller three-prong framework)
Commonwealth v. Crawley, 924 A.2d 612 (Pa. 2007) (standard of review for Atkins claims; substantial evidence review)
Commonwealth v. Sanchez, 614 Pa. 1, 36 A.3d 24 (Pa. 2011) (procedural framework for Atkins on collateral review; burden on defense)
Commonwealth v. DeJesus, Pa. - , 58 A.3d 62 (Pa. 2012) (confirms burden and Briseno considerations on collateral review)
Ex parte Briseno, 135 S.W.3d 1 (Tex. Crim. App. 2004) (factors relevant to adaptive functioning considerations)