Aaron S.J. Zelinsky

Special assistant U.S. attorney

Mr. Zelinsky, 36, was the first of the four prosecutors to file a withdrawal notice in federal court, which said that he had “resigned effective immediately” from his role as a special assistant U.S. attorney for the District of Columbia.

He will remain an assistant U.S. attorney for the District of Maryland, said Marcia Murphy, a spokeswoman for the U.S. attorney’s office in Maryland, where Mr. Zelinsky worked under Rod J. Rosenstein when Mr. Rosenstein was the top federal prosecutor in the state. Mr. Rosenstein went on to become the deputy attorney general.

Mr. Zelinsky played a central role in the prosecution of George Papadopoulos, a former Trump campaign adviser who pleaded guilty to lying to the F.B.I. about his contacts with Russian intermediaries during the 2016 presidential election. Mr. Papadopoulos served 14 days in jail.

Mr. Zelinsky clerked for Justice Anthony M. Kennedy before his retirement from the Supreme Court and for Justice John Paul Stevens after his retirement. He worked for the State Department during the Obama administration and received both his undergraduate and law degrees from Yale.

Adam C. Jed

Special assistant U.S. attorney

Mr. Jed, 38, was part of the cadre of lawyers who worked for Mr. Mueller on the 22-month Russia investigation. He entered the spotlight when he argued in pretrial litigation that certain records should be sealed from the public in order to protect the open investigation.

Mr. Jed had previously worked as an appellate lawyer for the Justice Department’s civil division, where he gained recognition in 2013 for arguing that a ban on gay marriage was unconstitutional.

He also clerked for Justice Stevens, according to Harvard Law Today, an alumni publication of the university where Mr. Jed got his law degree in 2008.