Whether Casassa established the affirmative defense of extreme emotional disturbance and was therefore entitled to have his murder conviction reduced to first-degree manslaughter.
Holding
No. Although the factfinder could accept that Casassa was emotionally disturbed, it could find that his disturbance had no reasonable explanation or excuse and therefore did not warrant mitigation.
Reasoning
New York's extreme-emotional-disturbance defense derives from the Model Penal Code and is broader than the former heat-of-passion doctrine. Unlike heat of passion, it need not arise from a single immediate provocation, and it may result from a substantial mental trauma that develops over time before emerging in the defendant's conduct. But the defense remains an affirmative defense, so the defendant bears the burden of proving it.
The defense has two components. First, the defendant must actually have acted while under the influence of an extreme emotional disturbance; this inquiry is wholly subjective and asks whether the asserted disturbance was real rather than fabricated. Second, there must be a reasonable explanation or excuse for that disturbance. The Court stressed that the reasonableness inquiry concerns the emotional disturbance, not whether the killing itself was reasonable.
The reasonable-explanation inquiry uses a mixed subjective-objective standard. The factfinder must consider the defendant's internal situation and the external circumstances as the defendant believed them to be, even if those beliefs were mistaken. From that perspective, however, the factfinder must still make an objective judgment about whether the claimed explanation or excuse was reasonable. The statute does not make every sincerely held, idiosyncratic emotional reaction mitigating.
The trial court applied that standard correctly. It considered Casassa's obsession, personality traits, and claimed mental disability, and it made a genuine effort to understand his perspective. Yet it could conclude that his reaction to Lo Consolo's rejection was so peculiar to him that it was not an understandable human response deserving leniency. The court therefore could regard the murder as an expression of malevolence rather than a disturbance with a reasonable excuse.