A white sedan put a man on the loading dock of a glbad and concrete building in a monotonous office district in southwestern Washington. The security guards quickly waved the vehicle, pressed a button that closed the garage door and protected the arrival of the guest from public view.
With his furtive arrival in the morning last week, White House counselor Donald F. McGahn II became the latest chain of high-level witnesses to enter the secret nerve center of Robert's special counseling S. Mueller III on Russian interference in the 2016 elections.
Twenty hours later, Mueller and his team came to the public eye to shake Washington with the dramatic announcement that former national security adviser Michael Flynn was I would plead guilty to lying to the FBI.
The capture of Flynn, the second former aide to President Trump to cooperate with the investigation, serves as the latest indication that Mueller's operation is rapidly pursuing an expansive mission, deepening Trump's inner circle.
In the past two months, Mueller and his aides have received private debri from two dozen current and former Trump advisors, each of whom walked to the special attorney's security office.
Amber Phillips of the Washington Post talks about what probably caused former President Trump's national security adviser, Michael Flynn, to turn to his former boss and cooperate with Mueller's investigation. (Jason Aldag, Amber Phillips / The Washington Post)
Once inside, most of the witnesses are sitting in a windowless conference room where groups of two and three people from FBI agents and prosecutors turn in and out outside, pressing them to get answers. 19659002] Among the topics that have been of great interest to researchers: how foreign government officials and their emissaries contacted Trump officials, as well as the actions and interaction of Flynn and Jared Kushner, the president's son-in-law.
Often the special counselor himself is the one listening, a presence similar to a sphinx that sits silently along the wall for some key interviews.
This image of Mueller's operation, drawn from the descriptions of witnesses, lawyers and other interviewees, provides a rare insight into the high-risk investigation that Trump's circle might involve and determine the future of his presidency.
The blocked nature of the probe has left both the witnesses and the reader scrutinizing each movement of the special counselor for meaning, without any certainty about the full scope of their investigation.
Trump and his lawyers have expressed confidence that Mueller will quickly conclude his White House exam, perhaps even by the end of the year. . Trump's Democratic opponents hope the investigation will uncover more crimes and ultimately force the president's ouster.
Meanwhile, some witnesses who were interviewed came away with the impression that the investigation is unfolding and is far from over.
"When they asked me, it seemed they were still trying to get an idea of the basic landscape of the place," said one witness who was questioned at the end of October for several hours and, like others, requested anonymity to describe the confidential sessions. "I did not have the feeling that they had anything that would incriminate the president, they were not even close to doing it."
White House attorney Ty Cobb said he believes that Trump's White House research approach is ending, and noted that all interviews with White House staff will be completed by the end of next week.  "At the end of the interviews, it would be reasonable to expect that it would not take long to bring this to a conclusion," Cobb said. "I congratulate the Office of the Special Adviser on its recognized hard work on behalf of the country, to take on this serious responsibility and carry it out in an accelerated but deliberate and exhaustive manner"
[Top FBI official badigned to Mueller’s Russia probe said to have been removed after sending anti-Trump texts]
At least two dozen people who traveled in Trump's orbit in 2016 and 2017 – in campaign, in its transition operation and then in the White House – have been questioned in the last 10 weeks, according to people familiar with the interviews
The most prominent profile is Kushner, who met with Mueller's team in November, as well as former chief of staff Reince Priebus and former press secretary Sean Spicer. The former foreign policy adviser J.D. Gordon has also been interviewed.
White House communications director Hope Hicks was scheduled to meet with Muller's team a few days before Thanksgiving. Mueller's team has also indicated plans to interview White House badociate advisor James Burnham and political adviser Stephen Miller.
McGahn, who was interviewed by Mueller prosecutors for a full day on Thursday, was due to return on Friday to complete his interview. However, the special attorney postponed the session as a courtesy to allow McGahn to help the White House manage the response to Flynn's statement, a person familiar with the interview said. Cobb refused to say what White House aides are left to interview.
Several people who worked side by side with Flynn were also interviewed by Mueller's operation. That includes retired General Keith Kellogg, chief of staff of the National Security Council, as well as several people who worked with Flynn Intel Group, a private consulting firm now undercover.
Mueller's group has also asked if Flynn specifically recommended overseas meetings with senior advisers, including Kushner. Investigators were particularly interested in how certain foreign officials got into Kushner's calendar and Flynn and Kushner's discussions about those encounters, according to people familiar with the questions.
During the transition, Kushner and Flynn met the Russian ambbadador to the United States, Sergey Kislyak. At the meeting in early December, Kushner suggested establishing a secure line of communication between Trump officials and the Kremlin at a Russian diplomatic facility, according to US officials who reviewed intelligence reports describing Kislyak's account.
Kushner said Kislyak was looking for the secure line as a way for Russian generals to communicate with the incoming administration about US policy on Syria.
Trump's son-in-law has also been identified by people familiar with his role as the "oldest member" of the transition team that Flynn led in December to approach Kislyak and lobby on a UN resolution on Israeli settlements, according to new court filings.
The volume of questions about Kushner in his interviews surprised some witnesses.
"I remember that they asked me specifically about Jared several times," said one witness.
Another witness said that agents and prosecutors repeatedly asked Trump about making decisions during the weekend of May, decided to dismiss the FBI director, James B. Comey. Prosecutors asked if Kushner had pushed the president to fire Comey, according to two people familiar with the interview.
Kushner's attorney, Abbe Lowell, declined to comment on what the president's son-in-law discussed in his November session with Mueller. "Sir, Kushner cooperated voluntarily with all the relevant investigations and will continue to do so," he said.
Two government officials said it would be natural for investigators to ask many questions about Kushner, whom Trump was in charge of communicating with foreign officials, adding that such inquiries do not indicate that he is a target.
The special attorney has continued to make continuous requests for records of badociates of the Trump campaign, according to two people familiar with the requests. Campaign partners are not expected to finish producing these documents before the end of the year. Mueller's team is also recently examining an office and advisers based in Alexandria who worked there on foreign policy for the campaign.
In recent weeks, Mueller's operation has approached new witnesses in Trump's circle, telling them that they can be asked to come for an interview. A person who was contacted recently said it is difficult to find a lawyer available to receive advice on how to interact with the special lawyer because so many Trump advisers have already hired lawyers.
"It was a bit painful," said the person. . "It's hard to find a lawyer who is not in conflict."
People who had shown up before Mueller's team describe polite but detailed and intense grills that have sometimes lasted all day and involved more than a dozen researchers. Spicer, for example, was in the office from approximately 10 a.m. until 6 pm. for your fall session. Mueller's team has recommended nearby places for lunch, but many witnesses bring food for fear of being discovered if they go outside.
Mueller has attended some interviews, introducing himself to witnesses as he enters and then sits along the wall. Sometimes he is joined by his friend James Quarles, a former lawyer and fellow lawyer at Watergate, who is the main point of contact for the White House.
Investigators bring large folders full of emails and documents to the interview room. One witness described the number of questions that arose each time an agent pbaded them a copy of an email in which they had been copied: "Remember this email? How does the White House work? How does the transition work? Who was taking the lead in foreign contacts? How did that work? Who was involved in this decision? Who was there that weekend? "
[Here are the people investigating Russian meddling in the 2016 election]
Some witnesses were introduced to so many federal agents and lawyers who later regretted that they had largely forgotten many of their names by the time a team left the room and a new team came in.
"They say: 'Hey, we're not trying to be rude, but people are going to go in and out a lot,'" explained a witness about the teams. "They enter and leave the room."
A contingent of investigators focuses on whether Trump tried to obstruct justice and avoid investigation into Russian meddling by firing Comey in May. Prosecutors Brandon Van Grack and Jeannie Rhee have been involved in matters related to Flynn.
Another team is led by former Justice Department fraud chief Andrew Weissman and foreign bribery expert Greg Andres. These researchers consulted lobbyists at some of the city's most powerful lobby stores about their interactions with former Trump campaign president Paul Manafort and campaign adviser Rick Gates.
Mueller's team accused Manafort and Gates last month of conspiring to hide millions of dollars in hidden foreign accounts and secretly creating an elaborate cover to hide their lobbying work for a former Ukrainian president and his pro-Russian political party. Both have declared themselves innocent.
Lawyers familiar with prosecutors' questions about Manafort said they expect several additional charges for this part of the case.
People familiar with Mueller's team said they convey a sense of calm that is disturbing.
"These guys are safe, awesome, quite friendly, they even joke a little," said one lawyer. When prosecutors play that kind of tone, he said, defense attorneys tend to think, "Uh oh, my boy is in a lot of trouble."
Rosalind S. Helderman contributed to this report.