Evidence of a meeting between U.S. President Donald Trump’s eldest son and a Russian lawyer with purported ties to Moscow has sent shockwaves through Washington.

The administration's detractors are claiming a chain of emails sent ahead of a face-to-face discussion in June 2016 amount to the first tangible evidence of collusion between Trump’s inner circle and Russian officials during the election campaign. The White House has been quick to dismiss any such notion.

The now publicly-available flurry of messages between Trump Jr. and a trusted intermediary promised documents that “would incriminate Hillary and her dealings with Russia.” The then-Republican candidate’s son replied within minutes: “If it’s what you say I love it especially later in the summer.”

Sen. Tim Kaine, a Virginia Democrat and Hillary Clinton's former running mate has gone so far as to say the meeting, which was first reported by the New York Times on Saturday, could amount to treason.

Two U.S. law enforcement professionals who spoke to CTV News Channel on Tuesday -- one from the CIA and the other from the FBI -- chose a more diplomatic word for now: problematic.

Former CIA officer Mike Baker and retired FBI special agent Kenneth Gray agree that so-called “opposition research,” meetings with individuals who may have actionable information about your rivals, has long been a textbook practice in high-stakes politics. But they warn the implications of this meeting now, given the multiple investigations underway into foreign meddling in the election, could go beyond typical campaign diligence.

“Oppositional research for political campaigns is an ugly world,” said Baker. “Whether it is inside your border or outside your borders, every campaign engages in it to some degree or another.”

For Baker, the problem lies in the fact that one side is shouting about serious crimes while the other says nothing of relevance occurred. Certainly, both cannot be true.

Gray said the substance of what was discussed in that meeting is not necessarily as meaningful as the fact that it actually took place.

“A meeting with people that have information about your opposition is pretty common, but a meeting with a foreign government, or a meeting with people that represent themselves as representatives of a foreign government, that in itself is a problem,” he said.

“The meeting itself may not have been a problem.”

Gray, who formally worked for Robert Mueller, the man now overseeing the U.S. Justice Department’s investigation into Russia’s alleged role in the 2016 election, does not see any obstruction of justice, official false statements, or perjury on Trump Jr.’s part, yet.

If the meeting was as benign as Trump Jr. claims, Gray wants that on the official record.

“If I were Robert Mueller, I would try to get Donald Trump Jr. before a federal grand jury and lock him into a statement,” he said. “Right now he has not made any sworn statements (about the meeting).”

Gray said it is entirely possible that Trump Jr. and other senior election aids were “hoodwinked” into agreeing to the meeting, assuming the parties in question held valuable intelligence that could sway the election when that was not the case.

Baker is also eager to see Mueller’s investigation move forward. But he feels it is naive to think such meetings have not gone on behind closed doors, in this election and others, and on both sides of the aisle.

“The Democrats were busy in Ukraine and Russia trying to compile information they thought would be damaging to Trump,” he said. “I object when people sound self-righteous and say that one side is clean and one side is not.”