NEW YORK (AP) — The suspect in the killing of UnitedHealthcare’s CEO is back in New York facing new federal charges of murder and stalking, escalating the case after his earlier indictment on state charges. Luigi Mangione agreed to return to New York after a Thursday morning court appearance in Pennsylvania where he was arrested last week. He appeared in a Manhattan federal court in the afternoon where a magistrate ordered he be detained. The federal complaint unsealed Thursday charges him with two counts of stalking and one count each of murder through use of a firearm and a firearms offense. Murder by firearm could bring the possibility of the death penalty.