Aaron Zebley, Mueller's chief of staff when he was FBI director
Zebley was an elite FBI agent for 7 years in the Counterterrorism Division
He was instrumental in tracking down dangerous Al Qaeda members back in 1999
He then became a prosecutor and one of Mueller's go-to confidants
He was part of the I-49 team: a small group of FBI agents based in NYC who were actively searching for Osama Bin Laden before the 9/11 attacks
James Quarles III, former Watergate investigator
A litigator and a partner at WilmerHale, where he started in 1975. He runs the DC office of the firm
He served as an assistant special prosecutor for the Watergate investigation
During that investigation, Quarles focused on campaign finance research — something that will certainly be called upon throughout the Russia investigation, particularly after the FBI issued subpoenas for financial disclosures from Michael Flynn and Paul Manafort
He has argued cases in front of the Supreme Court
Jeannie Rhee, former deputy attorney general in the Office of Legal Counsel
Rhee was senior adviser to former Attornery General Eric Holder for two years
She advised him and the WH on "constitutional, statutory and regulatory issues regarding criminal law, criminal procedure, executive privilege, civil rights and national security," according to WilmerHale.
She tried more than 30 cases when she served as an Assistant U.S. Attorney in the D.C. Attorney's Office
She rejoined WilmerHale as a partner in the Litigation/Controversy Department where she advised "clients who are the subject of government investigations" regarding "white-collar criminal investigations, False Claims Act allegations and securities enforcement matters."
In 2015, Rhee represented Hillary Clinton in a case about her private email server, according to Politico.
Andrew Weissmann, DOJ criminal fraud section chief
He was Mueller's one-time general counsel
Previously led the fraud unit at the DOJ
Weismann oversaw the Enron Task Force in the early 2000s, investigating the failed energy company
From 1991 to 2002, Weissmann handled cases against various crime families in NY as part of his work in the office of the U.S. Attorney for New York's Eastern District
He worked at a law firm where he focused on the Foreign Corrupt Practices Act, securities fraud, and other issues.
Michael Dreeben, DOJ's deputy solicitor general
Dreeben currently serves in the Justice Department, overseeing its criminal docket before the Supreme Court and handling its appellate cases
He has argued more than 100 cases in front of the Supreme Court
He was a deputy in the Office of the Solicitor General
He's been heralded as "1 of the top legal & appellate minds at DOJ in modern times," and has been called "the most brilliant and most knowledgeable federal criminal lawyer in America—period."
Lisa Page, an experienced DOJ trial attorney
There has been no official announcement from the special counsel about Page, but WIRED notes Mueller has reached out to her
Her investigatory expertise: organized crime cases, money laundering, and one particularly relevant case where she partnered with Hungary's FBI task force to investigate European organized crime.
Note: Her work in Hungary is what led to the ongoing money laundering case against Dmitry Firtash, a Ukrainian leader who was once business partners with Paul Manafort.