* Mangione's federal trial was most recently set for January

* Guilty plea could let Mangione seek dismissal of state

murder charge under double jeopardy law

* State trial on murder, weapons and forgery charges is

scheduled for September 8

(Rewrites paragraph 1 with Mangione guilty plea, admission)

By Jack Queen

NEW YORK, Aug 14 (Reuters) - Luigi Mangioneadmitted in court

on Friday to killing a health insurance executive and pleaded

guilty to federal charges of stalking the executive with the

intent to kill him.

The guilty plea will avert a federal trial in the closely

watched case over the killing of UnitedHealthcare CEO Brian

Thompson, a brazen crime that was condemned by public officials

but became emblematic of Americans' frustration with health

insurance industry practices. It could also allow him to seek

dismissal of state murder charges and delay an upcoming trial in

that case.

Mangione, 28, previously pleaded not guilty in April 2025 to

murder, weapons and stalking charges brought by Manhattan

federal prosecutors.

U.S. District Judge Margaret Garnett threw out the murder and

weapons charges over legal technicalities in a surprise ruling

in January 2026. The decision eliminated the possibility that

Mangione would face the death penalty in the federal case,

though he still faces a possible sentence of life without parole

if convicted on the remaining stalking charges.

His federal trial was most recently set for January.

Mangione separately pleaded not guilty in December 2024 to state

terrorism, murder, weapons and forgery charges brought by

Manhattan District Attorney Alvin Bragg. The terrorism charges

were thrown out by a judge in September 2025.

A trial in that case is scheduled for September 8 before Justice

Gregory Carro in Manhattan. Mangione would face 25 years to life

in prison if convicted of second-degree murder.

Resolving the federal case could allow Mangione to seek

dismissal of the murder charge under New York's double jeopardy

law, which protects people from being prosecuted twice for the

same conduct. Bragg's office would oppose the move, arguing that

the murder charge is legally distinct from the federal charges.

Whoever loses would likely seek an emergency appeal.

Thompson led UnitedHealth Group's ( UNH ) insurance unit before

he was shot dead in the early morning of December 4, 2024,

outside a hotel where an investor conference was taking place.

Graphic footage of the killing and a five-day manhunt for a

suspect made the case a media fixture and social media

sensation. Mangione was arrested in Pennsylvania.