NEW YORK (AP) — The man accused of killing UnitedHealthcare’s CEO was whisked back to New York by plane and helicopter Thursday to face new federal charges of stalking and murder, which could bring the death penalty if he’s convicted.

Luigi Mangione was held without bail following a Manhattan federal court appearance, capping a whirlwind day that began in Pennsylvania, where he was arrested last week in the Dec. 4 attack on Brian Thompson.

The 26-year-old Ivy League graduate had been expected to be arraigned Thursday on a state murder indictment in a killing that at once rattled the business community and galvanized some health insurance critics, but the federal charges preempted that appearance. The cases will now proceed on parallel tracks, prosecutors said, with the state charges expected to go to trial first.

Mangione, shackled at the ankles and wearing dress clothes, said little during the 15-minute proceeding as he sat between his lawyers in a packed federal courtroom.

He nodded as a magistrate judge informed him of his rights and the charges against him, occasionally leaning forward to a microphone to tell her he understood.

After the hearing, a federal marshal handed Mangione’s lawyers a bag containing his belongings, including the orange prison jumpsuit he had worn to court in Pennsylvania.

Mangione had been held in Pennsylvania since his Dec. 9 arrest while eating breakfast at a McDonald’s in Altoona.