There are 50 State Jurisdictions and a Federal Jurisdiction.
Luigi Mangione was charged under New York State laws, he was held by a state jail/prison.
These new charges are Federal. The feds took their time because he's already in a State jail/prison, so no need to rush the charges. They can take the time to plan on making an example out of him.
He was charged with murder in New York State. These are charges from the Department of Justice in a federal court, not the state court. This is how the Republicans are trying to make an example of him