ATLANTA (AP) — The Georgia prosecutor investigating the conduct of former President Donald Trump and his allies after the 2020 election is trying to compel U.S. Sen. Lindsey Graham and former New York Mayor Rudy Giuliani to testify before a special grand jury.

Fulton County District Attorney Fani Willis on Tuesday filed petitions with the judge overseeing the special grand jury. Fulton County Superior Court Judge Robert McBurney signed a “certificate of material witness” for Graham, Giuliani and others saying that they have been deemed necessary to the investigation.

Representatives for Giuliani and Graham did not immediately respond to requests for comment.

Willis also filed petitions for five other potential witnesses.