Luigi Mangione will return Tuesday to a New York courtroom — where a judge could reveal why he chose to bar the public from a recent hearing in the high-profile murder case.

The 28-year-old accused killer is due in Manhattan Supreme Court ahead of a September 8 trial where a jury will decide whether to convict him of executing UnitedHealthcare CEO Brian Thompson.

Tuesday’s proceeding will be held in full view of the public, in contrast to a mysterious “sealed” hearing that Justice Gregory Carro ordered earlier this month at the request of Mangione’s defense team.

It followed Carro last month handing prosecutors a key legal win by allowing jurors to see the alleged murder weapon — a 3D-printed pistol — and the “manifesto” found inside Mangione’s backpack when he was arrested in Altoona, PA., following a five-day manhunt.

Mangione has pleaded not guilty in parallel state and federal cases to charges of fatally shooting Thompson, a 50-year-old father-of-two, from close range on a Midtown sidewalk in December 2024.

But his lawyers have been stalling on revealing if they’ll use a psychiatric defense at his trial — a legal gambit that, if successful, could reduce his time in prison or result in him being institutionalized.

Carro did not explain why he blocked the public from accessing the June 3 pretrial hearing, but a New York State court system spokesperson hinted that a pending ruling in the case could shed light on the secrecy.

The judge also refused to let journalists challenge his decision to keep the hearing hush hush — despite state legal precedent stating that he must provide a “specific” reason for doing so.

Dozens of Mangione’s warped fans — who have praised him for highlighting the ills of the US healthcare system despite allegations that he executed the head of a major company in the process — have supported him at his past appearances.

Three of his most bloodthirsty cheerleaders, who dubbed themselves the “Mangionistas,” were even granted press passes by City Hall, in a baffling move that has drawn widespread condemnation.

The clean-cut scion of a wealthy Maryland family plotted to “rebel against the deadly, greed fueled health insurance cartel” by targeting the head of “a company that literally extracts human life force for money,” he wrote in notebook entries cited in court papers.

Mangione faces up to life in prison if convicted in either his state or federal case.