Washington (CNN) Attorney General Jeff Sessions returned to Capitol Hill on Tuesday for another round of heated testimony regarding what he knew about the Trump campaign's interactions with Russians.

Democrats pressed Sessions on his past denials, some of which are losing credibility as new reports emerge about contacts between Trump associates and Russians.

Since Sessions' previous testimony on the Hill in mid-October, President Donald Trump's son, Donald Trump Jr., acknowledged some private communications with WikiLeaks during the campaign. And unsealed court records revealed that Trump campaign adviser George Papadopoulos had repeated contacts with Russians and pleaded guilty to the FBI for lying about those contacts.

There isn't any evidence to suggest that Sessions knew about Trump Jr.'s private messages with WikiLeaks, though Trump Jr. did inform other senior members of the Trump campaign about the contacts. While Sessions was in the room with Papadopoulos during at least two campaign meetings, the attorney general testified that he didn't recall the meetings until he read about them in the news.

Here is a breakdown of Sessions' many denials and the relevant facts that later came to light. He vehemently denies lying under oath and denies participating in any collusion with Russia.

January 10, 2017: During his confirmation hearing, Sessions denied having any communications with Russians or knowledge of any campaign contact with Russians.

He was asked by Democratic Sen. Al Franken, "if there is any evidence that anyone affiliated with the Trump campaign communicated with the Russian government in the course of this campaign, what will you do?"

Sessions responded, "I'm not aware of any of those activities. I have been called a surrogate at a time or two in that campaign and I did not have communications with the Russians, and I'm unable to comment on it."

It was reported two months later that Sessions had met the then-Russian ambassador to the US, Sergey Kislyak, twice during the presidential campaign. Sessions acknowledged these meetings and said that they were part of his job as a senator and were unrelated to the campaign. Sessions also recused himself from overseeing the FBI investigation into Russian meddling.

January 17, 2017: Sessions denied having any campaign-related contacts with Russians in a written questionnaire submitted as part of his confirmation process.

The question from Democratic Sen. Patrick Leahy read, "Have you been in contact with anyone connected to any part of the Russian government about the 2016 election, either before or after election day?" Sessions provided a one-word reply: "No."

Two months later, Sessions acknowledged meeting Kislyak during the campaign, but he has maintained that their conversations were not about the presidential election.

June 13, 2017: Sessions denied under oath that he knew about any conversations between Trump campaign officials and Russians regarding interference in the election.

"I have never met with or had any conversation with any Russians or any foreign officials concerning any type of interference with any campaign or election in the United States," Sessions told the Senate intelligence committee . "Further, I have no knowledge of any such conversations by anyone connected to the Trump campaign."

At a March 2016 meeting of the Trump campaign's foreign policy team, Trump campaign adviser George Papadopoulos said that he, "had connections that could help arrange a meeting," between Trump and Russian President Vladimir Putin, according to court filings unsealed in October. Sessions was at the meeting. Papadopoulos pleaded guilty in October to lying to the FBI about his Russian contacts.

JUST WATCHED Rep. Lieu to Sessions: You lied then or now Replay More Videos ... MUST WATCH Rep. Lieu to Sessions: You lied then or now 01:21

October 18, 2017: Sessions testified that he was unaware of anyone in the Trump campaign, or campaign surrogates, having communications with the Russians before the election.

At a Senate judiciary committee hearing , Republican Sen. Lindsey Graham asked, "Did anybody in the campaign, did you ever overhear a conversation between you and anybody on the campaign who talked about meeting with the Russians?" Sessions replied, "I have not seen anything that would indicate collusion with the Russians to impact the campaign."

Franken later asked: "You don't believe that surrogates from the Trump campaign had communications with the Russians? Is that what you're saying?" Sessions replied, "I did not and I'm not aware of anyone else that did, and I don't believe it happened."

By the time of the hearing, communications between a handful of Trump associates and Russians had been reported in the press and, in some cases , confirmed by the Trump associates, including Donald Trump Jr. and White House senior adviser Jared Kushner.

The Papadopoulos case was unsealed a few weeks after this Senate hearing, revealing his contacts with Russians and that Sessions was privy to at least some off his communications. Sessions later testified that he remembered the meeting after seeing news reports about it.

November 14, 2017: Sessions testified that he didn't remember key details about meetings with Trump campaign advisers where they mentioned their communications with Russians.

"Frankly, I had no recollection of this until I saw these news reports. I do now recall the March 2016 meeting at Trump Hotel that Mr. Papadopoulos attended, but I have no clear recollection of the details of what he said during that meeting," Sessions told the House judiciary committee . "After reading his account, and to the best of my recollection, I believe that I wanted to make clear to him that he was not authorized to represent the campaign with the Russian government, or any other foreign government, for that matter."

Sessions also said he didn't recall talking about Russia with Trump campaign adviser Carter Page in summer 2016. Page recently told the House intelligence committee that he informed Sessions that he was going on a trip to Russia, as a private citizen, to speak at a university.

"As for Mr. Page, while I do not challenge his recollection, I have no memory of his presence at a dinner at the Capitol Hill Club or any passing conversation he may have had with me as he left," Sessions said about his knowledge of Page's trip to Moscow, which occurred in July 2016.