Back to the tax returns? Ex-federal prosecutor reveals why Trump’s financials are key to Mueller's investigation
Former FBI Director Robert Mueller. (Official White House Photo by Pete Souza)

New reports confirming that special prosecutor Robert Mueller has already conducted interviews with Attorney General Jeff Session and former FBI Director James Comey are signs that the obstruction of justice investigation is winding down, while the focus on President Donald Trump's financial entanglements will take months, Katy Tur's panel on MSNBC explained Tuesday.

"Barbara, does it look like this investigation is not winding down necessarily, but moving towards its conclusion?" Tur asked former federal prosecutor Barbara McQuade.

"I think you have to look at the two pieces of the investigation, the investigation regarding the overarching Russia scheme -- did Russia meddle in our election -- strikes me as one that might take many, many months to unfold," McQuade said. "It involves perhaps complex money laundering investigations, offshore bank accounts. that could take a long time. Then you have this other investigation into obstruction of justice with a smaller cast of characters, really just a few events that occurred over a short period of time. that one might be winding down."

"I don't see how any responsible prosecutor can ever investigate a case like this without looking at the finances. Whenever you are a prosecutor, one of the first things you do in any kind of white collar case is do a complete financial workup of the people who are the targets of the investigation," McQuade explained. "It tells you about who they are affiliated with, it suggests motives, if for example, people are in great debt to others, it could provide a motive to act in certain ways."

Natasha Bertrand, staff writer for The Atlantic, agreed that the financials were key to the investigation.

"This is exactly what he indicted Paul Manafort and Rick Gates on, he was following the money from the very beginning," said Bertrand.

"When it comes to trying to figure out whether Russia has any leverage on trump that would have compelled the Trump campaign to then coordinate with the Russians because they felt like they really had no choice, because they were kind of being held by kompromat the Russians had on them, investigating whether Donald Trump has a history of business relations with Russia is extremely important to determining why did the Russians interfere to try to get him elected."

"Is it because they thought they had a friend in Donald Trump, because they thought they had so much leverage over him in terms of his past financial dealings there, that they could essentially blackmail him once he was in office to get him to do their bidding?" Bertrand asked.