Flynn last year highlighted a Clinton aide's pleading the 5th Amendment Michael Flynn tweeted about a former IT aide of Clinton's taking the 5th.

 -- President Trump's former national security adviser, Michael Flynn, who is expected to take the Fifth Amendment in response to a Senate committee's subpoena, once promoted news of Hillary Clinton's computer-tech aide's invoking the same constitutional right.

"IT specialist takes 5th over 100 times," Flynn tweeted, linking to a June 22, 2016, story about the deposition of a former Clinton aide in a lawsuit related to her use of a private email server as secretary of state.

The Fifth Amendment gives an individual the right to protect against self-incrimination.

Flynn will plead the Fifth Amendment and refuse to honor a Senate Intelligence Committee subpoena request for documents relating to Russia's interference in the 2016 presidential election and its possible ties to Trump associates, a source close to Flynn told ABC News today.

"He will not be producing the documents they sought. He is entitled to decline, pursuant to the Fifth Amendment," the source said.

To date, Flynn is the only Trump associate whom the Senate has subpoenaed in its Russia investigation.

Last year, when Flynn was a prominent surrogate for Trump, he and others in the candidate's circle hammered the campaign of rival Hillary Clinton over the FBI investigation of emails. Flynn also jumped on news of Clinton's former IT specialist's pleading the Fifth Amendment when he was asked about her email setup during a deposition in June.

The tech specialist, Bryan Pagliano, was deposed as part of a lawsuit brought by the conservative group Judicial Watch.

"125 times - thats how many times @HillaryClinton IT guy invoked the 5th to cover up her server scandal," White House Press Secretary Sean Spicer tweeted in June.

Then-candidate Trump suggested that the aide's taking the Fifth implied guilt and he drew comparisons to the mafia.

“The mob takes the Fifth Amendment," Trump said at a rally in Iowa in September 2016. "If you’re innocent, why are you taking the Fifth Amendment?”

Trump himself pleaded the Fifth Amendment 97 times in 1990 during his divorce proceeding from former beauty queen Marla Maples, according to report in The Huffington Post.

Flynn's tweet on June 23 about the Clinton's aide's taking the Fifth Amendment came minutes after his son, Michael Flynn Jr., posted about it.

"Unbelievable," his son tweeted.

Flynn and his son were notably harsh critics of former Secretary Clinton and frequently focused on issues related to ethics when arguing against her candidacy.

In late October, just prior to Trump's election victory, Flynn called Clinton a "grifter" in a tweet, and claimed that the media had failed to adequately cover her "incredible corruption."

Responding to a question on Twitter from a user on July 6, 2016, asking what would have happened to Flynn had he acted as carelessly as Clinton while serving as director of the Defense Intelligence Agency, a post he held during President Obama's second term, he suggested that he would have been jailed.

"Removed, clearance revoked, subjected to intense investigation and put in jail," Flynn wrote. "She's guilty but will get away [with] it?"