In People v McKenzie (#133 decided 6/26/12) the Court held that, in determining whether to charge Extreme Emotional Disturbance in a homicide trial, "the relevant inquiry was whether the evidence, viewed most favorably to defendant, presented a triable question, we believe that the issue of the reasonableness of defendant's explanation should have been put to the jury." I believe that, while this language is not the precise formulation I was hoping for when I argued McKenzie, that it does support an argument I made at a recent CLE. Specifically, I think that if there is a valid line of reasoning and permissible inferences which would support a particular lesser, then the lesser must be charged - it's the same test as legal sufficiency for the prosecution. Otherwise the jury is being limited as trier of fact, and that function is effectively shared with the trial court.
The Court of Appeals stressed that "a court is bound to view the evidence in the light most favorable to the defendant ... an exercise understood to be incompatible with weighing the evidence to resolve competing inferences" (citation omitted), "The charge must be given if there is evidence reasonably supportive of the defense, even if there is other evidence which, if credited, would negate it". "Reasonably supportive", to my mind, is the same test as for legal sufficiency. The defense does not need to show that the jury should rule a certain way, or is likely to, merely that it would not be unreasonable or based solely on speculation.
The McKenzie decision is rooted in the EED statute: "the evidence would have permitted defendant's jury reasonably to conclude by a preponderance (Penal Law § 25.00 ) that, at the time of the homicide, he was affected by an extreme emotional disturbance, and that that disturbance was supported by a reasonable explanation or excuse rooted in the situation as he perceived it". However, the phrase "reasonably to conclude" I think goes to all defense requests for lessers.
An Appellate Division is not permitted to weigh the alternatives and find that the defendant's position is reasonable, but not reasonable enough. "Although, it is true, as the Appellate Division evidently found, that the evidence in the aggregate would have permitted the jury to reject defendant's claim of emotional disturbance and loss of control, it was instead the viability of the alternative, contrary inference - that defendant in fact experienced an emotional break which caused him to 'snap' - that should have guided the trial court's determination of the charge request." Neither the AD nor the trial court can weigh the facts: "A claim of extreme emotional disturbance must, of course, be credibly supported if the defense upon which it rests is to be submitted to the jury ... but that requirement was not intended to cast the trial court in the fact-finding role properly reserved to the jury" (citation omitted). A trial court is only permitted to deny a charge based on "objectively discernible deficiencies."
Specifically regarding EED, the mental infirmity required is simply a loss of self control (perhaps a "profound" loss of self-control). "The court denied the charge instead upon the ground that there was no proof that defendant had a 'mental infirmity that r[ose] short of a mental disease or defect.' But the purpose of this quoted language, as it has been used in our decisions to describe the predicate for an extreme emotional disturbance defense, patently was not to tether the defense to proof of an underlying psychiatric disorder; 'mental infirmity' in the presently relevant context refers more broadly to any reasonably explicable emotional disturbance so extreme as to result in and become manifest as a profound loss of self- control." (citations omitted). No psychiatric diagnosis is necessary ("it may be established without psychiatric evidence"), though one would obviously be relevant and helpful. The court recognized that a conviction for either murder in the second degree or manslaughter in the first degree represented "highly punitive options".
There was concern at the Court of Appeals regarding the necessity of charging EED in all domestic dispute homicides, and this is something to keep in mind for the future (the court held that the reasonableness of the EED "might well be understood to pose a closer question"). The decision was unanimous, opinion by Chief Judge Lippman.