- Peter Strzok, the second-highest ranking counterintelligence agent at the FBI, was involved at key junctures in the Hillary Clinton email investigation and the Trump-Russia probe.
- Strzok was reportedly the official responsible for changing language in former FBI director James Comey's statement describing Clinton's private email server use from "grossly negligent" - which could carry criminal penalties - to "extremely careless."
- Strzok was also the FBI agent who officially signed off on the bureau's decision to launch its Russia investigation in July 2016.
- Strzok was ousted from special counsel Robert Mueller's team last August after he sent anti-Trump text messages to a colleague, and investigators are now reviewing the texts for any evidence of political bias.
Peter Strzok, the counterintelligence veteran whom special counsel Robert Mueller cut from his team last August, played a key role at critical junctures of the FBI's investigation into former Secretary of State Hillary Clinton's use of a private email server, as well as its investigation into Russia's interference in the 2016 election, CNN reported.
As the deputy head of counterintelligence, Strzok was widely considered one of the most experienced investigators in his field at the FBI. He worked extensively on the bureau's inquiry into Clinton's use of a private email server to conduct government business before joining Mueller's team.
CNN learned on Monday that it was Strzok's decision to edit key language in a memo that former FBI director James Comey authored about the bureau's assessment of Clinton's actions.
The original draft of the memo, which was created in May 2016 and turned over to the Senate Judiciary Committee early last month, stated, "There is evidence to support a conclusion that Secretary Clinton, and others, used the email server in a manner that was grossly negligent with respect to the handling of classified information."
Around June 10, 2016, the memo's language was changed to say Clinton's actions were "extremely careless" instead of grossly negligent.
Though news of the change in language surfaced last month, documents turned over to the Senate Judiciary Committee did not indicate at the time that it was Strzok who was responsible for the edit.
Comey announced at a press conference in July 2016 that the DOJ would not file charges against Clinton because investigators did not have sufficient evidence to prove that she intended to act illegally.
"Although we did not find clear evidence that Secretary Clinton or her colleagues intended to violate laws governing the handling of the classified information, there is evidence that they were extremely careless in their handling of very sensitive, highly classified information," Comey said in July 2016.
"There is evidence to support a conclusion that any reasonable person in Secretary Clinton's position or in the position of those with whom she was corresponding about the matters should have known that an unclassified system was no place for that conversation," Comey added.
The former FBI director's announcement ignited swift and sustained criticism from Republican lawmakers and Clinton's critics who believed she had been treated with leniency. That scrutiny reemerged in full force last month, when news of the memo's change in language came out.
"Apparently, as of May 2016, then-Director Comey and other FBI officials believed the facts fit that gross negligence standard until later edits were made," Senate Judiciary chairman Chuck Grassley said in a letter to FBI director Christopher Wray. He also asked the FBI to elaborate on who was responsible for the change and the reasoning behind it.
The language change in the original draft is significant, legal experts said, because "gross negligence" comes with possible criminal penalties.
Strzok authorized the FBI to launch the Russia investigation
The FBI launched its investigation into Russia's election interference and possible collusion with the Trump campaign in July 2016, the same month Comey announced that the DOJ would not bring charges against Clinton.
According to CNN's report on Monday, Strzok was the FBI agent who signed off on officially opening the bureau's investigation into Russia's meddling.
Strzok made headlines last August when it was reported that Mueller had removed him from his team of prosecutors handling the FBI's Russia investigation.
The Washington Post reported Saturday that while Strzok was working on the Clinton email investigation, he exchanged texts expressing anti-Trump sentiment with an FBI lawyer, Lisa Page, with whom The Post said he was engaging in an extramarital affair. At the time, Page worked for Deputy Director Andrew McCabe.
Page and Strzok reportedly continued exchanging politically charged texts throughout the 2016 campaign season. Strzok was subsequently removed from Mueller's team after the inspector general began examining the messages.
Strzok's and Page's communications are now being examined for any evidence of bias in their handling of the Clinton and Trump investigations, according to The Post.
The Strzok-Page texts could fuel further demands from Trump and his defenders for a special counsel to examine how the bureau handled the investigation into Clinton's use of a private server to conduct government business. Officials are also reportedly concerned that news of the texts could spark further claims from the president and his allies that the Russia investigation is a political "witch hunt."