Andrew Weissmann—who built the case against Paul Manafort and one of the most prominent members of Robert Mueller’s team—is reportedly stepping down from the special counsel investigation. It’s the latest indication that Mueller’s work is nearly complete. NPR reports that Weissmann will also leave the Justice Department and now plans to study and teach at New York University while working on preventing wrongful convictions. Manafort was sentenced to about 7 1/2 years in federal prison following two cases that stemmed from Mueller’s investigation. However, neither case involved alleged collusion with Russia. One source told NPR that Weissmann’s departure is a clear sign that Mueller’s work is finally winding up—it follows the departure of the most senior FBI agent working on the Mueller probe, Special Agent in Charge David Archey, who has started a new job as head of the FBI’s office in Richmond, Virginia.