Luigi Mangione will assert psychiatric defence in murder case in UnitedHealthcare CEO’s killing

Luigi Mangione appears for a pre-trial hearing at Manhattan Criminal Court in New York, Wednesday, June 17, 2026. (AP Photo/Angelina Katsanis, Pool)

NEW YORK — Luigi Mangione will assert a psychiatric defence at his state murder trial in the killing of UnitedHealthcare CEO Brian Thompson, a judge said Wednesday.

Judge Gregory Carro said Mangione’s lawyers have informed him they will attempt to show that he was suffering from “extreme emotional disturbance at the time of the occurrence.”

By asserting a psychiatric defence, Mangione would effectively be admitting that he killed Thompson but did so because of mitigating circumstances.

If a jury finds that Mangione was emotionally disturbed at the time of the killing, it could convict him of manslaughter instead of murder, meaning he’d be sentenced to less time in prison.

It is not the same as a not guilty by reason of insanity defence, which would allow a defendant to go to a psychiatric facility instead of prison.

Carro’s ruling came two weeks after he held a secret hearing on the matter at the request of the defence. He said he will unseal records pertaining to the hearing and the defence’s move for a psychiatric defence.

“The reasons for the sealing was to give the defence an opportunity to determine whether they were going forth with that defence and the nature of that defence,” Carro said.

Mangione’s lawyer, Karen Friedman Agnifilo, said unsealing the transcript of the secret hearing and materials related to his psychiatric defence will harm him in his federal case.

“The reason why we asked for the sealing is that this defence is not available federally and Mr. Mangione is being prosecuted federally and this is prejudicial to his defence to the exact same facts,” Friedman Agnifilo said.

The judge had been set to rule on the matter on Tuesday, but delayed it a day because prosecutors failed to inform Mangione’s jail that he was needed in court.

Mangione sat between his lawyers wearing a blue suit and a light-coloured button-down shirt. He is set to go to trial on Sept. 8.

Mangione, 28, has pleaded not guilty to state and federal charges in the Dec. 4, 2024, killing. His federal trial, which involves stalking charges, is set to begin on Oct. 13. He could spend his life in prison if convicted in either case.

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.

Mangione, an Ivy League graduate from a wealthy Maryland family, was arrested five days later at a McDonald’s in Altoona, Pennsylvania, about 230 miles (about 370 kilometers) west of Manhattan. At a May 18 hearing, 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.”

Also Wednesday, Carro dismissed a charge related to a gun magazine that he had ruled inadmissible because it was found during an initial search of Mangione’s backpack at the McDonald’s.

Michael R. Sisak, The Associated Press