Luigi Mangione has been charged with federal and state crimes, including murder, stalking, and weapons charges, after allegedly killing the UnitedHealthcare CEO in New York. The federal charges are based on Mangione crossing state lines, which could lead to a federal murder charge and possibly the death penalty. The state charges include first-degree murder and terrorism, which are unusual for a single killing but increase the severity of potential penalties. Both federal and state prosecutions will proceed in parallel, with discussions ongoing about which will take precedence. Mangione's defense may focus on challenging the evidence and process, potentially arguing issues with evidence credibility or his mental state as mitigating factors.