NEW YORK — The man accused of gunning down UnitedHealthcare’s CEO outside a New York City hotel is unlikely to appear in Manhattan federal court again before mid-February after prosecutors and lawyers on Monday requested more time to prepare the case for trial.

The lawyers agreed in a letter to the court that the deadline to bring an indictment against Luigi Mangione can be extended from Jan. 18 to Feb. 17.

Mangione, 26, is now charged in a criminal complaint, a document that is lodged against individuals prior to the return of an indictment.

Prosecutors said they consulted with the defense and agreed that extending the deadline was necessary “to permit both parties adequate preparation for pretrial proceedings and the trial itself.”

Lawyers for Mangione and federal prosecutors declined to comment.

The case is unusual because at least one charge carries the possibility of the death penalty, but whether to pursue that penalty must be made by the Justice Department in Washington, where top officials will be changed as President-elect Donald Trump takes office later this month.

Authorities say Mangione fatally shot Brian Thompson on Dec. 4 as he was walking to an investor conference in midtown Manhattan.

The killing shocked the business community and galvanized some health insurance critics. Mangione posted frequently online about his struggles with back pain, though he was never a UnitedHealthcare client.

Federal charges against Mangione include murder and firearms counts. He made an initial appearance on the charges late last month. He won’t be required to enter a plea until an indictment is returned.

Mangione has pleaded not guilty in a New York state court to multiple counts of murder, including murder as an act of terrorism. Prosecutors have said the two cases will proceed on parallel tracks, with the state charges expected to go to trial first. His next appearance in state court is scheduled for Feb. 21.

The maximum sentence for the state charges is life in prison without parole.

Mangione was arrested Dec. 9 in a Pennsylvania McDonald’s following a five-day search. He’s being held in a Brooklyn federal jail alongside several other high-profile defendants, including Sean “Diddy” Combs and cryptocurrency fraudster Sam Bankman-Fried.