(CNN)Robert Mueller's team declined to prosecute Donald Trump Jr. and other members of the campaign for campaign finance violations for their participation in the June 2016 meeting at Trump Tower, in part, because they couldn't prove that they "willfully" violated the law.
"Taking into account the high burden to establish a culpable mental state in a campaign-finance prosecution and the difficulty in establishing the required valuation, the Office decided not to pursue criminal campaign-finance charges against Trump Jr. or other campaign officials for the events culminating in the June 9 meeting," Mueller's team explained.
"The Office ultimately concluded that, even if the principal legal questions were resolved favorably to the government, a prosecution would encounter difficulties proving that Campaign officials or individuals connected to the Campaign willfully violated the law," the team continues.
On June 9, 2016, Trump Jr., Jared Kushner, and then-campaign chairman Paul Manafort met with Russian lawyer Natalia Veselnitskaya at Trump Tower.
According to tweets published by Trump Jr. in July 2017, publicist Rob Goldstone sent Trump Jr. an email on behalf of his client Emin Agalarov to suggest the meeting regarding potential dirt on Clinton.
"This is obviously very high level and sensitive information but is part of Russia and its government's support for Mr. Trump," Goldstone, who represents Agalarov, the son of an Azerbaijani-Russian businessman close to Russian government, wrote in the email to Trump Jr.
"If it's what you say I love it," Trump Jr. replied, according to an email he released.
According to the Mueller report, Trump Jr. announced at a morning meeting of top campaign and Trump family members "that he had a lead on negative information about the Clinton Foundation" in the days before the Trump Tower meeting.
Then-deputy campaign manager Rick Gates, a top Mueller cooperator, recounted that Trump Jr. believed the information would come from a group in Kyrgyzstan -- potentially a reference to Aras Agalarov, Emin Agalarov's father and the Azerbaijani-Russian who helped to orchestrate the meeting, according to the special counsel.
Trump Jr., Eric Trump, Manafort, Hope Hicks, Ivanka Trump and Kushner all attended the morning meeting days before the Trump Tower meeting, with Ivanka Trump and Kushner attending late, according to Gates, Mueller wrote.
Manafort, however, cautioned the group to be careful and raised doubts that the upcoming meeting would actually yield vital information, Gates said.
Hicks later denied knowing about the Trump Tower meeting in advance, and Kushner said he did not recall if the Trump Tower meeting "came up at all earlier that week," according to the Mueller report.
Alan Futerfas, an attorney for Trump Jr., claimed the report vindicated the President's son.
"The report confirms that the June 9, 2016 meeting was just what Don said it was, and nothing more, and that there was nothing improper about potentially listening to information," Futerfas said in a statement.
