Before Zelinsky's appointment to the Mueller team, he worked under the man who appointed Mueller special counsel - Deputy Attorney General Rod Rosenstein. Zelinsky worked as an assistant U.S. attorney under Rosenstein during the latter's time as U.S. Attorney in Maryland. While in Maryland, Zelinsky earned an award for Excellence in Prosecution of Organized Crime. Additionally, Zelinsky has clerked for retired Justice John Paul Stevens and Justice Anthony Kennedy of the Supreme Court. Harold Koh, formerly of the State Department, has said he brought Zelinsky in as a special assistant at the State Department, where he worked the cases of Americans held hostage abroad. Koh calls Zelinsky "an incredible team leader."