ALTHOUGH THE BIPOLAR-DISORDER DIAGNOSIS WAS MADE “POST-CRIME,” THE EVIDENCE WAS RELEVANT TO DEFENDANT’S “MENTAL DISEASE OR DEFECT” AFFIRMATIVE DEFENSE AND SHOULD NOT HAVE BEEN PRECLUDED; NEW TRIAL ORDERED (FOURTH DEPT).

The Fourth Department, reversing defendant’s conviction and ordering a new trial, determined the psychiatric evidence regarding defendant’s “post-crime” mental health (bipolar disorder) was relevant to defendant’s “mental disease or defect” affirmative defense and should not have been precluded. The psychiatrist could not testify defendant suffered from “bipolar disorder” at the time of offense, but could testify that the disorder takes years to develop, which meets the flexible “relevancy” test:

Evidence is relevant if it has “any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence” … . …

We conclude that “[i]nasmuch as the psychiatrist’s [prospective] testimony that defendant was suffering from [bipolar disorder, type 1, most recent episode manic with psychotic features] would render a finding of lack of criminal responsibility more probable than it would be without such evidence, the [psychiatrist’s] diagnosis [was] . . . relevant” … . …

Here, although the psychiatrist did not evaluate defendant prior to the crimes and thus could not render a medical opinion that defendant had bipolar disorder on the date of the crimes, “there were indications in [his] testimony that the mental disease from which defendant was suffering could take [years] to develop [before diagnosis] and [that] . . . the [prior medical] records . . . suggest[ed] the existence of some mental disorder a considerable time before the crime[s]” … . …

Finally, we conclude that the error is not harmless … . The preclusion of the psychiatrist’s testimony effectively prevented defendant from mounting his affirmative defense (see Penal Law § 40.15) and severely undermined his ability to separately argue that he lacked the requisite mental state to commit the charged offenses … . Inasmuch as ” ‘it cannot be said that there is no reasonable possibility that the error contributed to the verdict, the error cannot be deemed harmless beyond a reasonable doubt and reversal therefore is required’ ” … . People v Williams, 2026 NY Slip Op 04095, Fourth Dept 6-26-26

Practice Point: Consult this decision for insight into the relevancy of evidence. Here a post-crime bipolar disorder diagnosis was deemed relevant to defendant’s “mental disease or defect” affirmatve defense.​