ST. PETERSBURG — Former FBI Director Robert Mueller is now in charge of the investigation into any possible links between President Donald Trump's campaign and the Russian government.

He's the special counsel Democrats had long been demanding.

Republicans followed with many speaking out after the president fired FBI Director James Comey lawmakers are comparing the situation to Watergate, with some calling for impeachment.

The White House did release an official statement from President Trump. Here's what it reads:

"As I have stated many times, a thorough investigation will confirm what we already know-- there was no collusion between my campaign and any foreign entity. I look forward to this matter concluding quickly," the statement reads.

Don't expect any quick answers. This kind of investigation is expected to take a while.

The term "special prosecutor" has been coming up a lot but there are a lot of questions about exactly what Mueller's role will be.

Here are the big points you need to know.

Mueller has really broad powers to investigate. He can subpoena - force people to tell the truth under penalty of perjury, and he's doesn't have to immediately share his findings with the Justice Department.

That means he's pretty independent - outside of the normal chain of command.

But the big question I had - how is this any different than the Trump-Russia investigations going on in the House and Senate?

To find out, I called up my favorite constitutional law professor, Lou Virelli with Stetson University.

“A special prosecutor can actually bring criminal charges. Again, (I) don't know if those charges are going to be forthcoming, don't know if they're even merited at this point, but a special prosecutor can bring them in the Senate cannot,” Virelli said. “So, it looks much more like a criminal investigation at this point because all of the authority of a criminal prosecutor is vested in former FBI director and our special prosecutor Mueller.”

The other big thing I wanted to know was - OK, who is this guy?

Robert Mueller is a former FBI director - he took office in 2001 and ran the Bureau for 12 years under Presidents George W. Bush and Obama.

He’s very well respected.

He is also the one in charge of figuring out whether President Trump or his associates did something illegal and what actions to take.