Buzzfeed reports that Special Counsel Robert Mueller has turned his attention to Donald Trump’s eldest son. The review seems to be particularly interested in the meeting Trump Jr. chaired in Trump Tower on June 9, 2016.

Trump Jr. has acknowledged that he was looking for negative information about Hillary Clinton when he, as well as Jared Kushner and then-campaign manager Paul Manafort, met with the lawyer. But he claimed he did not receive any useful opposition research.

Previous reports indicated that Donald Trump’s campaign chair Paul Manafort was under close examination from the Special Counsel’s office both for his magical, no-collateral loans and his flow of funds from overseas. The pairing of Manafort and Trump Jr. as central to the investigation, may suggest that Mueller considers that Trump Tower meeting—which also included Jared Kushner, a Russian attorney with ties to the Kremlin, representatives for a Russian real-estate firm, and a man who had started over 2,000 shell companies for money laundering—as a critical moment. It was a meeting that combined an offer of interference by the Russian government on the behalf of Donald Trump, and one that included many different firms involved in Trump’s emergence as a conduit for moving money out of Russia. 

While some reports have suggested that Mueller is looking deeply into Trump’s financial activities, including some that are many years in the past, this report seems heavily aimed at the central question of the Trump campaign’s relationship with the Russian government.

That prosecutorial muscle is reportedly bearing down on a variety of people in Trump’s campaign for possible collusion with Russian efforts to sway the election and other issues. Mueller is said to be looking at whether Trump obstructed justice in any way in his conversations with and eventual firing of FBI director James Comey.

We may now be focused on Trump’s response to white supremacist terrorism, and before that we spent a week watching Trump raise the security temperature over North Korea. But even if the rest of the nation was momentarily diverted, that doesn’t mean Mueller looked away.

Just because the investigation into Trump Jr. is mainly concerned with events directly related to the campaign, there are some people who are still not off the hook for their other actions.

And Manafort, whose residence was searched last month, is reportedly facing Mueller’s scrutiny not just for his role in the June 9 meeting but also for his dealings in Ukraine, where he was a consultant for a pro-Russian Ukrainian political party. Michael Flynn, Trump’s former national security adviser, is reportedly under investigation for communications with Russia’s ambassador and his representation of a Turkish firm.

Trump had previously drawn a “red line,” stating that it would be “going too far” for Mueller’s investigation to look into his finances. During July, hostility between Trump and Attorney General Jefferson Sessions focused on Sessions recusing himself from the Russia investigation, and it seemed possible that Trump would fire Sessions as part of an effort to dismiss Special Counsel Mueller.