By Marlene Lenthang, Adam Reiss and Antonio Planas

    Luigi Mangione, the suspect indicted in the murder of UnitedHealthcare CEO Brian Thompson, waived his right to an extradition hearing and was flown from Pennsylvania to New York on Thursday afternoon to face federal charges.

    Mangione, 26, appeared Thursday morning in Blair County, Pennsylvania, for a preliminary hearing, where he waived extradition and was subsequently taken into New York police custody.

    He was also hit with new federal charges unsealed Thursday: two counts of stalking, murder through use of a firearm and a firearms offense.

    A clean-cut Mangione entered federal court in lower Manhattan on Thursday afternoon wearing beige slacks and a white shirt under a black V-neck. Before the hearing, Mangione picked up the charging sheet and appeared to read it carefully.

    During the hearing, U.S. Magistrate Judge Katharine H. Parker read the four federal charges that were unsealed earlier Thursday. She asked Mangione whether he understood the charges, and he responded, “Yes.”

    Parker ruled Mangione will be detained until his next hearing in mid-January. He will be jailed at the Metropolitan Detention Center in Brooklyn, a senior official told NBC News.

    After the hearing, one of Mangione's lawyers, Karen Friedman Agnifilo, said outside the courthouse that his defense team is reserving comment.

    “We’re going to respectfully decline to make any comment this time. Mr. Mangione appreciates everyone’s support," she said.

    Mangione now faces federal charges in New York and 11 New York state charges in the ambush shooting of Thompson, as well as charges in Pennsylvania.

    In a statement from federal prosecutors with the Southern District of New York, acting U.S. Attorney Edward Y. Kim said the state case against Mangione is expected to go to trial before the federal case.

    Thompson was fatally shot on Dec. 4. as he was walking in front of a midtown Manhattan hotel to speak at a UnitedHealth Group investor conference.

    Federal charges

    The federal stalking charges allege that Mangione traveled across state lines from Georgia to New York with the intent “to kill, injure, harass, intimidate” and surveil Thompson and that he used electric communications, interstate highways and the internet to carry out “the stalking, shooting and killing of Brian Thompson.”

    The complaint, written by a special agent with the FBI, shed new light on the notebook Mangione was found with when he was arrested in Altoona, Pennsylvania, on Dec. 9.

    The notebook contained “several handwritten pages that express hostility toward the health insurance industry and wealthy executives in particular,” the federal complaint said.

    An entry marked for the date of Aug. 15 said that “the details are finally coming together” and that “the target is insurance” because “it checks every box.”

    An entry marked Oct. 22 said: “1.5 months. This investor conference is a true windfall,” the complaint said. Later on, that entry described an intent to “wack” the CEO of one of the insurance companies at the investor conference. That date was six weeks before the Dec. 4 murder, the day of UnitedHealth Group’s investor conference.

    In a letter addressed “To the Feds,” Mangione wrote “I wasn’t working with anyone” and said his actions were “self-funded,” the complaint said.

    Extradited from Pennsylvania to New York

    Mangione was attentive during his hourlong morning hearing in Pennsylvania and appeared to smile with his attorney.

    After the hearing wrapped up, Mangione, dressed in an orange jumpsuit, was ushered out of the courthouse and placed in a black SUV.

    Around 10:40 a.m., a motorcade of New York City police and Pennsylvania State Police was seen at Altoona-Blair County Airport, where Mangione was loaded on a small plane to travel to New York. The flight took off about 10 minutes later. He arrived at MacArthur Airport on Long Island shortly after noon.