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Pool/Getty; Tyler Le/BI

2025-12-13T10:00:01.241Z

• Lawyers are fighting over evidence in the murder of UnitedHealthcare CEO Brian Thompson.
• They are also sparring over such terms as "execution," "manifesto," and "Faraday."
• Here’s a look at this war of words and what it means for accused killer Luigi Mangione.

Yes, it’s a fight over a backpack — how it was seized, how it was searched, and whether the gun and notebook found inside will be tossed or kept as knockout-blow evidence in a future murder trial.

But Luigi Mangione’s ongoing evidence suppression hearing, playing out for two weeks in a Manhattan courtroom, is more than that.

The serious legal battle features an often amusing undercard bout: repeated** **sparring over nothing more than the naming of things.


Lead defense lawyer Karen Friedman Agnifilo speaks with Luigi Mangione, at the defense table in New York Supreme Court in Manhattan. Mangione is charged in the shooting murder of UnitedHealthcare CEO Brian Thompson. Sarah Yenesel - Pool/Getty Images

Was UnitedHealthcare CEO Brian Thompson shot on a Midtown sidewalk last year? Or was he "executed?"

Is the red notebook found inside Mangione’s backpack a "manifesto," or a "journal?"

And is the aluminum-lined pouch found in Mangione’s backpack a "Faraday bag," meant to block his cellphone from being tracked during a five-day manhunt? Or was the bag simply "waterproof?"

It all depends on who is standing at the courtroom’s podium: lead defense lawyer Karen Friedman Agnifilo or top prosecutor Joel Seidemann.


Assistant District Attorney Joel Seidemann outside the offices of Manhattan DA Alvin Bragg. Laura Italiano/Business Insider

These pretrial rhetorical rumbles foreshadow how intensely these two adversaries — seasoned legal veterans with decadeslong experience — will fight next year, at a yet-scheduled trial in the same state-level courtroom.

The temperament of the judge is also being previewed. NY Supreme Court Justice Gregory Carro has alternated between seeming mildly irked and utterly unfazed as he’s refereed these sporadic wars of words over the past two weeks.

"Move on," Carro has said when** **the prosecutor and defense lawyer complain about each other — like when Friedman Agnifilo stood up on Thursday to say of Seidemann, "He wants to play the word ‘manifesto’ over and over and over again!"


Mangione’s journal. Manhattan DA’s Office/Business Insider

Carro’s relative calm has only wavered once, on Monday, after the prosecutor repeatedly referred to Thompson’s murder as an "execution."

"You testified you were aware of the New York City shooting?" Friedman Agnifilo had asked the third Altoona, Pennsylvania, cop to take the stand. (Mangione was arrested in a McDonald’s there five days after Thompson’s December 4, 2024, shooting, after being spotted by customers.) "You were aware it did not involve a bomb?" she asked, scoring a point.

"Were you aware it involved a premeditated execution?" Seidemann clapped back minutes later, visibly eager to take that point back.

The judge’s voice was sharp as he sustained Friedman Agnifilo’s objection. Soon afterward, she stood to complain about the prosecutor’s repeated references to "manifesto" and "the execution of Mr. Thompson."

"He certainly won’t do that at trial," the judge warned.

"I’ll bear that in mind, your honor," the prosecutor answered.


The Faraday bag and Apple cell phone found inside Luigi Mangione’s backpack. Manhattan DA’s Office/Business Insider

A small "Faraday bag," featuring a protective lining that blocks electronic signals, triggered an extended semantic skirmish on Tuesday.

Both the lawyer and the prosecutor were asking a lot of questions at the time, about this one little pouch. The size of a business envelope, it held an Apple cellphone, Mangione’s passport, and a small wallet with a driver’s license and three charge cards inside.

In questioning the officer who first pulled it out of the backpack, Friedman Agnifilo referred to the pouch as "a black bag that has Velcro."

She also called it a "waterproof bag," noting that other items in the backpack had been damp that day. (The same cop had testified that inside the backpack she’d found a gun clip filled with nine hollow-point rounds — all wrapped in a pair of gray underwear that was "soaking wet.")


Items inside a small Faraday bag included Luigi Mangione’s passport, a wallet, and four identification and charge cards. Manhattan DA’s Office/Business Insider

Weren’t electronics and a passport "items that you’d want to keep dry?" Friedman Agnifilo asked. "Yes," the officer answered.

Seidemann wasn’t having it.

"Is that a Faraday bag or a waterproof bag?" the prosecutor asked on his next turn at the podium, pointing to a photograph of the pouch.

"It’s a Faraday bag," the cop answered.

"And how do you distinguish a Faraday bag from a waterproof bag?" Seidemann pursued.

"This bag had an aluminum lining," the cop answered.

Seidemann paused briefly.

"If we can continue," he then said, turning toward the audience with a slight smile.

Mangione’s evidence suppression hearing is scheduled to conclude next week. The judge has yet to say when he will rule on the admissibility of the backpack and its contents.

The Baltimore native is challenging the admissibility of evidence in both his state and federal murder prosecutions. Trial dates have yet to be set in both cases.

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