Was appointed Robert Mueller by Obama

What you need to know about Robert Mueller

How far does the investigation go?

The appointment of Robert Mueller as a special investigator empowers him to identify "possible links and / or coordination between the Russian government and people close to President Donald Trump and his election campaign". The appointment also states - and this could significantly expand his work - that the special investigator can examine "any matter" that arises or could arise directly from the investigation ", as well as" any matter under 28 CFR ยง600.4 (a) ".

This section relates to the legal jurisdiction of a special investigator and empowers him or her "in connection with federal offenses committed during the work of the special investigator or with the aim of obstructing his work, such as perjury, obstruction of justice, elimination of evidence or intimidation of witnesses to investigate and conduct interrogations resulting from the investigation ".

This means that while the original investigation focused on possible links between the Kremlin and Trump's campaign team, the investigation can now be expanded if the results suggest it. In light of recent events surrounding the firing of FBI chief James Comey, it is noteworthy that the special investigator may also investigate possible "obstruction of justice" or "intimidation of witnesses".

"That is in the nature of investigations: once you research something, you quickly notice that it is also related to other things," says Prof. James Davis, director of the Institute for Political Science at the University of St. Gallen in Switzerland .

What is Robert Mueller's history?

It was Republican President George W. Bush who appointed Robert Mueller as FBI director in 2001. Mueller remained at the head of the agency until 2013, even under Bush's successor, Barack Obama. The fact that the New York-born lawyer is very concerned about his independence and is not easily intimidated by political pressure is shown by an incident which, interestingly, also includes James Comey.

The sacked FBI Director James Comey is a good friend of Robert Mueller

In 2004, then-FBI director Mueller and Comey, who was then deputy attorney general, rejected White House calls to re-allow eavesdropping on private homes by the Bush administration after the September 11, 2001 attacks. When Bush overruled their objection with his veto, both threatened to resign until the White House assured them that the regulation would be revised.

"Mueller has a reputation for integrity in both political camps, as well as with the FBI and the Justice Department, so I think he's a good choice," said Davis.

What are the powers of a special investigator?

In essence, a special investigator has the same powers as an ordinary federal prosecutor, except that he works outside the normal hierarchy of justice. Special investigators have their own budget, can hire their own employees and investigate, summon and prosecute people.

How independent is the special investigator from the Trump administration?

If it's true, as they say, the White House learned just an hour before the public that a special investigator had been appointed, it could indicate that the Justice Department is trying to show that this is indeed an independent investigation.

This is also relevant because the two highest representatives of the Justice Department have basically withdrawn from the Kremlin investigation: Justice Minister Jeff Sessions had already resigned from the investigation in March due to bias. And since his deputy Rod Rosenstein wrote the recommendation to dismiss James Comey, he is now also involved in the Russia Comey affair and will therefore try to stay away from the investigation as much as possible.

"Everything was done so that he could work as independently as possible," says Davis.

"If the president has something to hide, the investigation is very dangerous for him."

How dangerous is that for President Trump himself?

"If the president has something to hide, it's very dangerous for him," says Davis, because Mueller will follow whatever direction the investigation takes him. "We just don't know what kind of pressure the president will put on Mueller. But I'm sure he will be up to the task."

Of course, as the president has said, it may well be that the investigation will not reveal any wrongdoing by Trump.

How long will the investigation last?

There is no time limit on the investigation and, at this point in time, it is impossible to say how long it will take and what the outcome will be. Mueller will first need time to set up his investigative office before he can begin his actual work. How long the examinations then take depends on what he finds out or what he doesn't find out.

"That will keep us all busy through the summer and into the autumn and maybe, depending on the result, even beyond," said James Davis from the University of St. Gallen.