A team of lawyers lead by former FBI Director Robert Mueller is currently leading an investigation into President Donald Trump. This began on May 17th, 2017, when Mueller was hired by the Justice Department as special counsel to look into Russian interference in the 2016 election and any potential collusion between the Trump campaign and the Russian government.

A special counsel like Mueller is allowed to hire his own staff, and Mueller has now assembled a team of 13 investigators, according to CNN. However, at this time, only five members of this team have been identified.

President Donald Trump has attacked the lawyers investigating him, suggesting that they are “bad and conflicted” people.

You are witnessing the single greatest WITCH HUNT in American political history – led by some very bad and conflicted people! #MAGA — Donald J. Trump (@realDonaldTrump) June 15, 2017

So who exactly are these people currently in charge of investigating the president of the United States? Here’s a look at Robert Mueller’s team.

Michael Dreeben

Michael Dreeben is the current deputy solicitor general in charge of the Department of Justice’s criminal docket before the Supreme Court. He has worked in the Solicitor General’s office since the late 1980s, and he is considered to be an expert in criminal law, having argued over 100 cases before the Supreme Court.

According to The Washington Post, Dreeben is “highly respected by Democrats and Republicans because of his encyclopedic knowledge of criminal law.”

“Michael is the most brilliant and most knowledgeable federal criminal lawyer in America — period,” Walter Dellinger, a law professor at Duke University School of Law and former acting solicitor general, told The Washington Post. “I learned early on in my time as acting [solicitor general] that there was no point of ever thinking of second-guessing Michael on a matter of federal criminal law, because he just knew more than I did or could ever know. He’s a straight shooter and is held in the greatest esteem by the FBI and lawyers in U.S. attorneys offices all over the country.”

Some in the conservative media have accused Michael Dreeben of donating to Democrats, including Barack Obama and Hillary Clinton. But this is actually not the case; that Democratic donor is a different person also named Michael Dreeben, according to Slate. There is no relation.

Dreeben is expected to continue overseeing the Department of Justice’s appellate cases while he works on the Russia probe.

James Quarles

James Quarles has plenty of experience with political investigations, as he begin his career by working on the Watergate Special Prosecution Force. According to Wired, during the Watergate investigation, he focused on campaign finance research.

“There is nothing comparable to the kind of pressure and obligation that this kind of job puts on your shoulders,” Richard Ben-Veniste, a lawyer who served as a special prosecutor during the Watergate scandal, told CNN. “Having been there before, gives [Quarles] the confidence to know how to do it and how to do it right.”

In addition, Quarles is a partner at the law firm WilmerHale, where he has worked since 1975. This is the law firm where Robert Mueller also previously worked. After Quarles was presented with an award in 2007, his colleague, Partner William Lee, said that Quarles “represents precisely the values that should define us culturally and reputationally: he is an excellent lawyer, he is an extraordinary hard worker, he is the ultimate team player, he treats everyone with respect and collegiality. He always, always puts the firm first and himself second.”

According to Find Law, Quarles has particularly focused on issues of intellectual property litigation. He has argued before the United States Supreme Court and the Court of Appeals for the Federal, First, Second, Third, Fourth, Sixth and District of Columbia Circuits.

James Quarles has donated over $30,000 to Democrats over the years, including Barack Obama and Hillary Clinton, according to Open Secrets.

Jeannie Rhee

Jeannie Rhee has experience working in the U.S. Department of Justice, where she was Deputy Assistant Attorney General in the Office of Legal Counsel. According to WilmerHale, in this position, she “advised the Attorney General, the White House and senior agency officials on constitutional, statutory and regulatory issues regarding criminal law, criminal procedure, executive privilege, civil rights and national security.”

Rhee previously served as Assistant US Attorney in the US Attorney’s Office for the District of Columbia. Her other past jobs include legislative fellow in the office of former Senator Tom Daschle, counsel in the US Department of Justice’s Office of Legal Policy, law clerk for the Judith Rogers of the US Court of Appeals for the District of Columbia Circuit, and law clerk for Stanley Sporkin of the US District Court for the District of Columbia.

Rhee once represented Hillary Clinton in a lawsuit over her use of a private email server, according to Politico.

Like several of her colleagues on the Russia investigation, Jeannie Rhee previously worked at the law firm WilmerHale, where she was a partner in the Litigation/Controversy Department. According to WilmerHale, she primarily advised clients “who are the subject of government investigations, including white-collar criminal investigations, False Claims Act allegations and securities enforcement matters.”

Rhee has donated over $15,000 to Democratic candidates over the years, including Hillary Clinton, according to Open Secrets.

Andrew Weissmann

Andrew Weissmann serves as the chief of the criminal fraud section of the U.S. Department of Justice. He is taking a leave of absence from the Department of Justice in order to work on the Russia probe.

“Andrew Weissmann is an extraordinary attorney with an incomparable dedication to the pursuit of justice,” Assistant Attorney General Caldwell said when Weissman became chief of the DOJ’s criminal fraud section. “As his deep experience demonstrates, many of the top officials throughout the Department of Justice have come to rely upon his wise counsel over the years, and I am pleased to welcome him back to the Criminal Division.”

From 1991 to 2002, Weissmann worked in the office of the U.S. Attorney for the Eastern District of New York. In this position, he tried a number of crime families including the Gambinos. In addition, from 2002 to 2005, Weissmann served as director of the task force investigating the Enron scandal. This was the Justice Department’s investigation into fraud at the American energy company Enron.

Weissmann has previous experience working with Robert Mueller. When Mueller was director of the FBI, Weissmann served as his general counsel, according to the U.S Department of Justice.

In addition, Weissman worked at the law firm Jenner & Block for five years, “where he worked on a broad range of matters including ones involving securities fraud, antitrust, health care fraud and the Foreign Corrupt Practices Act,” according to the Department of Justice.

Weissmann donated $2,300 to the 2008 campaign of Barack Obama, according to Open Secrets.

Aaron Zebley

Finally, Aaron Zebley is a member of the Russia probe. He’s a former FBI official who has worked with Robert Mueller before.

Zebley spent seven years as special agent of the FBI in the Counterterrorism Division, also serving as chief of staff to Robert Mueller. In addition, he is a former Assistant US Attorney in the National Security and Terrorism Unit in Alexandria, Virginia, according to WilmerHale.

He is an expert in cybersecurity, and he brought this expertise to the table when he joined the law firm WilmerHale as a partner in 2014.

“Aaron’s experience at the Bureau, Main Justice and the US Attorney’s Office will add to our internal investigations, crisis management and cybersecurity capabilities,” Robert Novick, co-managing partner of WilmerHale, said in a statement when Zebley was hired. “He will provide immeasurable value in areas where we are already strong and growing.”

Zebley once represented Hillary Clinton aide Justin Cooper, who played a key role in Hillary Clinton’s set up of a private email server, according to CNN.