With the impeachment hearings focusing on the Trump administration's dealings with Ukraine, Trump's personal Attorney, Rudy Giuliani, has taken center stage with a career diplomat describing Giuliani's engagement with the country "an irregular channel."

"It seems to me he is fundamentally confused between representing Donald Trump the individual and Donald Trump the President of the United States. And you can't do both necessarily," said former district attorney John Moscow.

Before becoming mayor, Giuliani was the U.S. Attorney for the Southern District of New York. He now might be under investigation from the very office he used to run.

Critics say if Giuliani has done anything improper, he certainly should have known better.

"For Rudy Giuliani, it's just a different phase of his career. No matter what you thought of him before, good or bad, it's an extremely odd way to end one's career in the legal profession," said attorney Josh Liston.

As for possible charges Giuliani could be facing, they tie directly to the House inquiry and whether the former Mayor was acting in an official capacity.

"If he is not acting as an agent of the government, by what right is he dealing with foreign governments? You have a Logan Act problem, possibly. You have a Foreign Agent Registration Act problem, possibly. You have mail fraud and wire fraud, possibly," said Moscow.

Reports say federal prosecutors are also eyeing whether Giuliani stood to profit from a natural gas company deal in Ukraine.

"When you are America's Mayor and lauded for all you have done in the past it can lead to hubris and also the need to make money can lead people to make bad choices," said Liston.

Giuliani has denied any wrongdoing, but there is no question that all the facts about what he was doing in Ukraine and whether he was acting as an agent of President Trump have not yet been brought out.