After months of speculation that Russia and the Trump campaign worked together, explicit evidence has emerged in emails released by Donald Trump Jr. They say he agreed to sit with a Russian government attorney in June 2016 after he was told Moscow wanted to help the Republican candidate undermine Hillary Clinton. Josh Robin filed the following report.

Donald Trump Jr. released it himself: an email chain legal experts say could result in criminal charges.

The exchange is with publicist Rob Goldstone. He emailed in June 2016 at the request of a musician whose father has deep ties to the Putin regime and who had recently met with a Russian prosecutor. That prosecutor "offered to provide the Trump campaign with some official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father."

"This is obviously very high level and sensitive information but is part of Russia and its government's support for Mr. Trump."

Seventeen minutes later, Donald Trump Jr. replies, "If it's what you say I love it."

The president says in a statement, "My son is a high-quality person and I applaud his transparency."

Trump Jr. says in retrospect, he would have done things differently.

"For me, this was opposition research," he said. "They had something, maybe concrete evidence to all of the stories that I had been hearing about that were probably underreported for years, not just during the campaign. So I think I wanted to hear it out."

The White House says the president wasn't aware of the meeting. The president, and his son, have also denied any Russian involvement in the campaign. But those denials are, now, by Trump Jr.'s own admission, untrue.

PR worries may be the least of it. 

"It's always hard to say what's illegal completely, but there's a good argument that that falls within the language of the statute," said election law expert Richard Briffault.

A statute, Briffault says, prohibiting soliciting something of value from a foreign national in a federal election campaign.

That national is a Russian lawyer who met with Trump Jr. June 9. She now says she didn't have compromising information. 

Trump Jr. also says nothing came out of the meeting. But expecting something would may be all that matters.

Also in attendance that Thursday, campaign manager Paul Manafort and Ivanka Trump's husband Jared Kushner, now a White House aide.

Experts say special prosecutor Robert Mueller likely wants all of them to give their sides, which could yield more problems.

"We don't know where this is going," Briffault said.