Luigi Mangione is scheduled to appear at Manhattan federal court on Monday morning in relation to the murder of UnitedHealthcare executive Brian Thompson.

Mangione stands accused of the 4 December 2024 killing of Thompson on a New York City street. He faces murder and weapons charges in his state-level case, and stalking counts in the federal proceedings.

Thompson’s death not only prompted an extensive manhunt for his killer, but renewed attention on Americans’ longstanding dissatisfaction with the US for-profit healthcare industry. Mangione himself has also spurred a small but vocal contingent of supporters known as Mangionistas.

Mangione has pleaded not guilty in both cases.

Mangione’s planned Monday appearance comes shortly after his state case spiraled into uncertainty. Judge Gregory Carro, who is overseeing Mangione’s state-level case, revealed on 17 June that his lawyers wanted to pursue a psychiatric defense.

Carro said that Mangione’s team planned on invoking an “extreme emotional disturbance at the time of the occurrence” to defend him. The judge also ordered Mangione’s lawyers to tell prosecutors what “mental defect” Mangione allegedly suffered during the shooting.

Carro also said he would be “unsealing the record” from a 3 June conference that was behind closed doors, despite reporters’ requests for an open proceeding. Court proceedings are presumed public in New York state and the US with rare exceptions; members of the press and public have a right to petition for access; Carro did not entertain arguments for access prior to this proceeding.

This record would involve the a 250.10 notice, Carro said. This is a defense team proclamation that “he was proceeding with an affirmative psychiatric defense … extreme emotional disturbance [EED] at the time and place of the occurrence”.

The transcript was unsealed on 18 June and shed light on why lead Mangione attorney Karen Friedman Agnifilo might have wanted to keep this proceeding under wraps.

“As you know, your honor, if a defendant goes with an EED defense, they’re essentially admitting publicly that they committed this crime,” she said.

About the same time this transcript was unsealed, however, a letter from Mangione’s defense indicated that they would be withdrawing this 250.10 notice. Carro then said that due to the 250.10’s withdrawal, his prior sealing order would stand.

While it had been widely reported that the withdrawal of this 250.10 notice meant Mangione would not pursue a psychiatric defense, a legal expert—who has mounted several extreme emotional disturbance defenses—said that he could still do so.

A 250.10 notice means that Mangione’s defense would have to share whatever psychiatric information with prosecutors, including an expert’s assessment. Mangione’s defense could still try to show mental distress – potentially by putting him on the stand, or using prosecutors’ evidence to show severe unwell – in the hopes of securing a manslaughter verdict over a murder conviction.