Luigi Mangione was arraigned in a New York City courtroom Monday, as the city continued proceedings against the Baltimore native who has been charged with murder in the Dec. 4 shooting death of UnitedHealthcare CEO Brian Thompson.

Mangione comes from one of the wealthiest families in Baltimore and was valedictorian at the elite Gilman School in Baltimore.

Mangione pleaded not guilty on Monday to state charges brought by New York prosecutors in the killing. Mangione is facing murder as a crime of terrorism, murder in the first degree, murder in the second degree, criminal possession of a forged instrument and seven counts of criminal possession of a firearm in the state.

He quietly answered “not guilty” to each count in the courtroom, which had a public gallery filled with around two dozen female supporters.

Many of those supporters were wearing face masks and waited for hours in the freezing temperatures outside to get public seats. “This is a grave injustice, and that’s why people are here,” one of the women told ABC News.

Mangione appeared before Manhattan Supreme Court Justice Gregory Carro dressed in a maroon sweater, white button suit and khaki slacks, a stark departure from the orange jumpsuit he wore during his Pennsylvania court proceedings.

Mangione also wore a similar cleaned-up look in his appearance before a judge on federal charges on Dec. 19., as well as a new haircut and shave.

Mangione’s defense lawyer Karen Friedman Agnifilo complained Monday that Mangione was being used as a political tool by, among others, New York City Mayor Eric Adams, who she said was behind the high-profile “perp walks” of her client.

Friedman Agnifilo called the media-heavy appearances “perfectly choreographed, utterly political” and “absolutely unnecessary.” She also said Mangione is being used as “political fodder.”

Friedman Agnifilo scolded Adams for whipping up public sentiment about her client’s case by politicizing his prosecution.

“I am very concerned about my client’s right to a fair trial in this case. He is being prejudiced by some statements made by public officials,” she said Monday. “He is a young man, and he is being treated like a human ping pong ball.”

FBI Special Agent Gary Cobb wrote in a federal criminal complaint filed Thursday that a notebook that Luigi Mangione allegedly had on him when he was arrested outlined specific plans to target a health care CEO.

In an entry dated “10/22,” court docs say Mangione allegedly wrote that he planned to “wack” an executive in the sector, a note which followed an earlier entry from “8/15” that said “the target is insurance” because “it checks every box,” adding “I’m glad – in a way – that I’ve procrastinated, bc it allowed me to learn more about (acronym for Company-1).”

Mangione’s attorney told a court Monday that her client may not be able to get a fair trial in Manhattan.

A coalition of lawmakers looking to put new guidelines on the country’s third largest company, UnitedHealthcare, amid the death of Thompson earlier this month is drawing scrutiny because of the inclusion of Sen. Elizabeth Warren, D-Massachussetts, who made several controversial comments about the popularity of the suspect charged in the crimes, Baltimore native Luigi Mangione.

“The visceral response from people across the country who feel cheated, ripped off, and threatened by the vile practices of their insurance companies should be a warning to everyone in the health care system,” Warren said on Dec. 11. “Violence is never the answer. But people can only be pushed so far.”

One of Warren’s colleagues, outspoken independent Bernie Sanders, from Vermont, agreed that the reaction to Mangione as a folk hero has roots in a deeply flawed American health care system.

“[It] tells us is that millions of people understand that health care is a human right and that you cannot have people in the insurance industry rejecting needed health care for people while they make billions of dollars in profit,” Sanders said, adding that the killing itself was “outrageous.”

Contact Riley Gutierrez McDermid at rmcdermid@baltsun.com.