A case argued Wednesday at the state Supreme Court has the potential to change how the insanity defense is adjudicated in New Jersey criminal cases.

First Assistant Deputy Public Defender Judith Fallon asked the court to create a bifurcated system whereby a defendant has a chance first to prove an affirmative defense and, if unsuccessful, proceed to a trial on whether he is not guilty by reason of insanity.

Her client, Robert Handy, was found insane and committed to a mental hospital without ever getting a jury to hear his claim that he acted in self-defense when he stabbed his uncle to death.

Handy, of Paterson, had a long-standing history of mental illness and was diagnosed before trial as suffering from intense paranoid schizophrenia.

Superior Court Judge Joseph Falcone found him incompetent to stand trial and declared him not guilty by reason of insanity. Under the Appellate Division’s ruling in State v. Khan, 175 N.J. Super. 72 (1980), Falcone’s finding precluded a second trial in which Handy could have presented his self-defense claim.

On appeal, another Appellate Division panel partially reversed, saying Khan was no longer good law and that the standard should be changed. Defendants asserting an affirmative defense, but who also have questions regarding their mental state, should be allowed to assert their affirmative defenses. However, the panel ruled that if the defendant chooses to move ahead with an affirmative defense, he or she must relinquish the use of the insanity defense as a fallback position.

Fallon argued on Wednesday that there should be bifurcated trials in which the insanity option remains a possibility.

More important for Handy, she said in State v. Handy, A-68-11, was that Handy should be allowed to prove that he acted in self-defense.

“It’s always been Robert Handy’s position that he acted in self-defense,” Fallon said. “He has yet to be able to argue that he acted in self-defense, but not for lack of trying. He may be in a hospital for the rest of his life with a very good self-defense case going unheard.”

Chief Justice Stuart Rabner asked how a system could be crafted that would accommodate two inconsistent defenses.

Fallon said the bifurcated system would be tailored only for a defendant who wants to present an affirmative defense without being forced to abandon the insanity defense. “This is a small, discreet subset of cases,” she said.

Justice Barry Albin was skeptical, remarking, “You can’t say he didn’t do it and then say he was insane when he did it.” Albin added that having a bifurcated trial could prevent a jury from hearing potentially relevant evidence that could help it decide an issue of competency.

“I agree that it seems to be illogical,” Fallon said. “But I don’t think there’s anything wrong with letting one jury deciding if he acted in self-defense.”

Justice Jaynee LaVecchia asked Fallon to address the issue of a unitary trial in which the jury would be allowed to consider both defenses.

“That would relieve the state of its burden to make its case,” Fallon said, noting it would be a “foregone conclusion” that the jury could take the easy way out and adopt the verdict of not guilty by reason of insanity rather than allow the defendant to go free.

Deputy Attorney General Ashlea Thomas urged the court to adopt the unitary trial procedure, saying it was the “most appropriate” method.

“The jury will have all the evidence,” she said. “You can trust jurors to separate the issues.”

LaVecchia asked what type of instructions should be given to jurors in situations such as Handy’s.

“It would depend on each case,” Thomas replied. “But it is undisputed that anyone, including those with mental illnesses, has the right to defend themselves. Structured properly, unitary trials would allow juries to consider both defenses.”

Albin suggested that a jury might not accept a claim of self-defense if there were a competing argument that the defendant acted because of his or her mental illness.

Thomas said there may be the “unique case” with “unique facts” that could justify having bifurcated trials like those suggested by Fallon. “But I’m not going to say what those facts are,” she concluded.