Updated at 5:43 p.m. | A review of open-source data indicates then-candidate Donald Trump was inside Trump Tower last year when his eldest son and at least two other top aides huddled with a Russian lawyer they believed had Kremlin-supplied information that could hurt presidential rival Hillary Clinton.

White House and Trump campaign officials, along with the president’s private legal team, have not disputed as of publication time that he was at his Manhattan steel-and-glass haven. That means Trump was nearby — though likely on a different floor — when his son and associates believed they were about to receive information from the Kremlin intended to ding another candidate for the country’s highest office.

“Mr. Mueller will almost certainly want answers, under oath, clarifying whether President Trump was made aware at the time of the existence of the meeting in general, to say nothing of the specific details of the meeting,” said Bradley Moss, a national security lawyer, referring to Justice Department special counsel Robert S. Mueller. “He will also want to know whether President Trump was debriefed about the meeting at any time in the aftermath.”

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The meeting on June 9, 2016, at Trump Tower in New York with Natalia Veselnitskaya — whom a Trump family business associate described to Donald Trump Jr. in an email as a “Russian government attorney” — was premised on her delivering Kremlin-supplied information the associate assured Trump’s eldest son “would incriminate Hillary and her dealings with Russia and would be very useful to your father.”

In the June 2016 email exchange, Trump Jr. replied, “I love it,” to the associate, entertainment publicist Rob Goldstone.

“This is obviously very high level and sensitive information,” Goldstone wrote to Trump Jr., “but is part of Russia and its government’s support for Mr. Trump.”

The president, Trump Jr., and others in their orbit have downplayed the significance of the meeting. Trump said Thursday that “most people would have taken that meeting.”

Much surrounding the meeting remains to be disclosed, and lawmakers and experts say Mueller will want to answer those lingering questions.

What we know

Candidate Trump appears to have been inside the Manhattan tower when Trump Jr., son-in-law and senior adviser Jared Kushner and campaign chairman Paul Manafort met with Veselnitskaya. The Associated Press reported Friday that Rinat Akhmetshin, a Russian-American lobbyist, also attended the meeting. 

The Trump campaign was in something of a travel pause during the time of the meeting: The Republican nomination had recently been sown up, and the focus in Trump World was to pivot to the general election and Clinton, who was on track to become the Democratic nominee.

Trump was in New York on June 9. The campaign held rallies in California the previous week, in San Jose on June 2 and Redding on June 3. Trump and his aides then hunkered down in Manhattan as they turned their focus toward the Republican National Convention and a race against Clinton. The next campaign rally was a full week later: Friday, June 10 in Richmond, Virginia.

On June 9, Trump attended a fundraiser at the Four Seasons Hotel in midtown Manhattan, not too far from Trump Tower. In a bit of foreshadowing, a source in the Four Seasons room that day told NBC News that Trump described a general election strategy centered on expanding the electoral map. (He would go on to win Wisconsin, Michigan and Pennsylvania which observers considered safely in Clinton’s pocket.)

Trump left the Four Seasons en route to his tower shortly after 1 p.m., according to multiple June 9 media reports. He remained at Trump Tower for the rest of the day, according to open source data.

A White House official referred a reporter to the president’s personal legal team, but did not dispute that Trump was in the building when the meeting occurred.

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Attempts were made to discuss Trump’s exact whereabouts that day with two members of Trump’s outside legal team, Marc Kasowitz and Jay Sekulow. Kasowitz did not respond to a direct email; Sekulow did not respond to a request sent via the American Center for Law & Justice, where he is chief counsel.

What we don’t know

For starters: What the elder Trump knew, and when he knew it.

Trump — echoed by Principal Deputy Press Secretary Sarah Huckabee Sanders and his personal lawyers — initially said he only learned of the meeting with the Russian lawyer in recent days. But then, in an off-the-record chat Wednesday night with reporters aboard Air Force One that the White House then made on-the-record, the president further muddied the waters when he suggested the meeting might have come up in passing.

Trump was referring to the issue of adoption in general, Huckabee Sanders responded via email, not the June 9 meeting. She also provided a portion of the White House’s official transcript of the Air Force One conversation; previously, only other select parts had been made on-the-record and distributed to White House reporters.

“Nobody talked to me, no. In fact, I mean, maybe it was mentioned at some point, but I don’t remember ever hearing about adoption,” Trump said. “You know, adopting babies from Russia was a big thing, and it was ended, but that was a big thing. But during the campaign, I mean, I may be wrong, I don’t remember anybody ever bringing it up as an issue.”

Asked if he had been told at the time that the session was supposed to be about dirt on Clinton, Trump said no, according to reporters who were on the plane.

“He was clear he had not heard about story until a few days ago,” Huckabee Sanders said of Trump’s comments en route to Paris.

Moss, the national security lawyer, suggested viewing Trump’s public comments about the matter as “political spin,” adding that “what matters is what he ultimately states under oath in a deposition.”

“It’s reasonable to suspect that the president will be somewhat more cautious in that context than he has been publicly,” Moss said, “and will state something akin to: ‘I do not recall hearing about the meeting at that time.’”

During a Tuesday evening interview with Fox News’ Sean Hannity, Trump Jr. was asked what his father knew last June about the meeting.

Hannity: “A lot of people are going to want to know this about your father. Did you tell your father anything about this?”

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Trump Jr.: “No. It was such a nothing. There was nothing to tell. I mean, I wouldn’t have remembered it until you start scouring through the stuff. It was … literally just a wasted 20 minutes, which was a shame.”

If Mueller concludes Trump Jr. is being truthful about what he did not tell his father, Moss said “the president being in Trump Tower at that time, in and of itself, is much ado about nothing.”

“It only has any relevance for Mr. Mueller if the president was aware of the meeting and why it was taking place, or was debriefed at the time about what had occurred,” the national security lawyer said.

What it means

There is little question the Trump Jr. emails only added to the scandal engulfing the family and its patriarch’s turbulent presidency. With his domestic agenda stalled, some Republican lawmakers, for instance, are practically begging the president to drop his Twitter habit.

Rep. Adam Kinzinger, for example, told CNN on Friday morning that he believes the president’s often-incendiary tweets are a distraction, arguing he should instead focus on his policy agenda. The Illinois Republican is hardly alone in his feelings.

Trump Jr.’s own words seem to have ruffled the feathers of senior GOP leaders who are key to Trump’s agenda, as well as many rank-in-file members. House Speaker Paul D. Ryan of Wisconsin told reporters Thursday he thinks Trump Jr. should testify on Capitol Hill about the meeting. And Texas Rep. Bill Flores said Thursday he thinks “it would be in the President’s best interest if he removed all of his children from the White House.”

The bottom line

Based on all publicly available information, experts like Moss say Manafort and former Trump campaign adviser and later White House national security adviser Michael Flynn could face criminal charges, as could Trump Jr., if Mueller concludes they violated federal campaign laws.

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“At a minimum, Don Jr. is now likely to have the entirety of his communications with anyone affiliated with or associated with the Russian government scrutinized and picked apart,” Moss said. “The purpose of doing so is to see if this was just a one-off on his part or if it was part and parcel of a larger plan to coordinate or collaborate with individuals claiming to represent the Russian government in some capacity.”

The significance of the June 9 meeting with the Russian lawyer and Trump Jr.’s enthusiastic acceptance of what he was told was campaign assistance from the Russian government depends on what Mueller finds out about what the president knew at that time.

“Based on the current available public information, I do not see any reason to suspect he would face impeachment charges for any collusion that might have occurred, as it does not appear he personally was aware of what his subordinates were doing,” Moss said. “The greatest threat to the president is not what happened during the campaign but rather his own ability to control his temper and avoid interfering with the investigation.”