Luigi Mangione’s lawyers called the cold-blooded slaying of UnitedHealthcare CEO Brian Thompson a “single, tragic event” – as they argued the admitted killer’s guilty plea triggers double jeopardy.

Defense attorney Karen Friedman Agnifilo told reporters outside the Lower Manhattan federal courthouse that Mangione, 28, accepted full responsibility for the health executive’s death with his guilty plea – which unfolded during a dramatic hearing just minutes before.

She then laid the groundwork for arguing that Mangione’s murder charges in state court should be tossed after his plea.

Luigi Mangione, 28, speaks in Manhattan federal court on Friday. Jane Rosenberg/ Reuters

Luigi Mangione pleaded guilty to federal stalking charges on Friday in Manhattan federal court. Jane Rosenberg/ Reuters

Luigi Mangione, 28, speaks in Manhattan federal court on Friday, where he pleaded guilty to federal stalking charges in the killing of UnitedHealthcare CEO Brian Thompson. Jane Rosenberg/ Reuters

Follow The Post’s live updates on Luigi Mangione’s guilty plea in UnitedHealthcare CEO shooting

“It was a single tragic event, yet he’s being persecuted twice for the same conduct,” Agnifilo said.

Mangione’s lawyers filed a motion in Manhattan criminal court arguing that his plea in federal court triggered double jeopardy, Agnifilo said.

But Manhattan District Attorney Alvin Bragg’s office appeared ready to fight it.

“While federal sentencing is pending, we are prepared to litigate the defense motions. The Manhattan D.A.’s Office remains committed to seeking justice for Mr. Thompson and his family,” a spokesperson said in a statement.

“Since December 2024, the Manhattan DA’s Office has been tirelessly preparing to pursue a trial conviction in New York State Supreme Court for the alleged cold-blooded murder of Brian Thompson,”  the statement said.

Defense lawyer Karen Friedman Agnifilo speaks to the media outside Manhattan Criminal Court in New York City on August 14, 2026. REUTERS

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“We are encouraged that Mr. Thompson’s family received a measure of accountability today.
Mangione’s family.”

Jury selection in the state case is set to start Sept. 8.

Mangione will face up to life in prison when he’s sentenced in the federal case Dec. 18.