He says he "thought it was a very strong signal", adding: "They do that very seldom". It also seems pretty reasonable to think that during his days on the fringe that Manafort wasn't always on the right side of American financial laws.
While following the money trail can uncover critical clues in any white-collar crime investigation, Trump recently warned that any digging into his finances would be a violation of Mueller's mandate.
According to Veselnitskaya, Manafort spent the entire meeting looking at his cellphone.
Manafort was campaign manager during the convention in Cleveland, when the Republican platform was changed to reflect a pro-Russian position on Ukraine.
Investigators are looking into accusations of money laundering in an attempt to pressure Manafort into cooperating with the probe into the Trump campaign's possible ties to Russian Federation, two sources told Reuters.
Manafort also attended a meeting previous year at Trump Tower with Trump's son Donald Trump Jr., son-in-law Jared Kushner, and two Russian lobbyists who were said to have offered dirt on Hillary Clinton.
Asked whether he had spoken to Attorney General Jeff Sessions or the Federal Bureau of Investigation about the raid, Trump said: "I have not, but to do that early in the morning, whether or not it was appropriate, you'd have to ask them".
But the statements stood in contrast to what Mr. Trump has privately told people close to him in recent months.
"The grand jury is often engaged in investigations of both the prosecutor's office and the FBI. In addition, given the obvious unlawful deficiencies, this extraordinary invasive tool was employed for it shock value to intimidate Mr Manafort", said Dowd.
The US Attorney General is normally in charge of determining if the Justice Deparment needs a special counsel to lead an investigation. Manafort has already given about 300 documents to Congress.
Josh Rosenstein, an attorney at Sandler Reiff Lamb Rosenstein & Birkenstock who specializes in FARA, said that although prosecutions under the act are quite rare, it is a "distinct possibility" that Mueller's team could pursue one against Manafort.
Last week, The New York Times reported that investigators asked the White House for documents related to Flynn and have questioned some witnesses about payments Flynn may have gotten from the Turkish government.