A hearing for Luigi Mangione's state murder trial in the killing of UnitedHealthcare CEO Brian Thompson was postponed until Wednesday after prosecutors said they failed to inform his jailors that he was needed in court.

Photo: Reuters/ Steven Hirsch/ File

Judge Gregory Carro had scheduled the hearing for Tuesday but adjourned it about a half-hour after its scheduled start when Assistant District Attorney Joel Seidemann informed him that prosecutors had failed to send required paperwork to the jail.

Seidemann noted that the judge in Mangione's federal case, Margaret Garnett, had sent an order to the jail authorising him to wear a suit to court, but the prosecutor acknowledged that alone wasn't enough to get him brought to court.

Mangione, 28, is being held at a federal jail in Brooklyn while awaiting trial in state and federal trials in the Dec. 4, 2024, killing. He has pleaded not guilty in both cases and could spend his life in prison if convicted in either case.

Carro had been expected to rule Tuesday on an unspecified matter after holding a secret hearing two weeks ago. Carro said he sealed the virtual proceeding at the request of the defence but provided no other details at the time.

Luigi Mangione, who was arrested in December 2024 and charged with fatally shooting UnitedHealthcare CEO Brian Thompson on a sidewalk in Midtown Manhattan, sits next to his lawyers Marc Agnifilo and Karen Friedman Agnifilo before Justice Gregory Carro at an evidence suppression hearing at the Manhattan Supreme Court in New York City, U.S., May 18, 2026, in a courtroom sketch. REUTERS/Jane Rosenberg

Any ruling from Carro would now come on Wednesday.

Mangione is set to go to trial in the state case on September 8. His federal trial, which involves stalking charges, is set to begin on October 13.

Thompson, 50, was killed as he walked to a Manhattan hotel for UnitedHealth Group's annual investor conference. Surveillance video showed a masked gunman shooting him from behind. Police say “delay,” “deny” and “depose” were written on the ammunition, mimicking a phrase used to describe how insurers avoid paying claims.

Defense lawyers Jacob Kaplan, Marc Agnifilo and Karen Agnifilo sit before Judge Gregory Carro in court representing Luigi Mangione, who was arrested in December 2024 and charged with fatally shooting UnitedHealthcare CEO Brian Thompson on a sidewalk in Midtown Manhattan, during a hearing in New York City, U.S., June 16, 2026 in a courtroom sketch. REUTERS/Jane Rosenberg

Mangione, an Ivy League graduate from a wealthy Maryland family, was arrested five days later at a McDonald's in Altoona, Pennsylvania, about 370 kilometres west of Manhattan.

At a hearing last month, Carro ruled that a gun and notebook that prosecutors say link Mangione to the killing can be used as evidence against him.

The gun, a 3D-printed pistol, matches the one used to kill Thompson, prosecutors said. The notebook describes wanting to “wack” a health insurance executive and rebelling against “the deadly, greed fueled health insurance cartel.”