Under New York law a defendant must give advance notice before offering psychiatric evidence. This filing preserves the defense’s right to present expert testimony that, at the time of the killing, Mangione acted under the influence of an extreme emotional disturbance for which there was a reasonable explanation.

EED is an affirmative defense, not a claim of insanity. The defense is not arguing Mangione could not tell right from wrong; it is arguing his mental state at the moment should reduce the level of the offense. If a jury accepts it, second-degree murder becomes first-degree manslaughter — still a serious felony, but not the top count.

Because the defense chose this route, the prosecution is entitled to have Mangione examined by its own psychiatric expert, and both sides’ experts are expected to testify at trial.

Justice Carro confirmed the defense would be permitted to argue extreme emotional disturbance and unsealed related filings. Around the same time the court dismissed a magazine-related count, leaving second-degree murder as the top charge the EED defense is aimed at.