On Monday, the FBI’s reputation with regard to its investigation into Hillary Clinton, Russian collusion with the Trump campaign, and its investigation into Trump officials including former National Security Advisor Michael Flynn, took a serious hit. That hit came courtesy of FBI agent Peter Strzok, who was fired by Robert Mueller’s special investigation for alleged bias against President Trump. That bias was uncovered based on texts from Strzok apparently signaling his distaste for Trump.

Strzok wasn’t just any agent. Here are some of the events in which he was involved.

He Interviewed Hillary Clinton And Helped Exonerate Her. Not only did Strzok lead the investigation into Hillary’s email server, he interviewed Hillary herself. He also drafted the language responsible for allowing Hillary to escape prosecution — instead of labeling her behavior grossly negligent, he classified the behavior as “extreme carelessness.”

He Was Involved In The Investigation Into The So-Called Russian Dossier. According to Fox News, Strzok briefed the House Intelligence Committee on December 5, 2016, but an informant told the committee that Strzok was allegedly obstructing a probe into the dossier; Strzok was reportedly involved in the transmission of the dossier to the FBI.

He Interviewed Mike Flynn. On January 24, Strzok and one other agent interviewed Flynn, according to an intelligence official. According to one source, Strzok’s boss, Andrew McCabe, contacted Flynn by phone and said that “some agents were heading over (to the White House) but Flynn thought it was part of the routine work the FBI had been doing and said they would be cleared at the gate. … It wasn’t until after they were already in (Flynn’s) office that he realized he was being formerly interviewed. He didn’t have an attorney with him.”

It’s not clear whether Mueller fired Strzok upon finding out about his anti-Trump text messages; if so, that would actually boost Mueller’s credibility. And it’s also true that Strzok was a top agent, and would have been tasked by Comey to let Hillary off the hook. However, Strzok’s involvement in every area touching the collusion and Hillary investigations, and his known bias, throws the entire investigation into chaos.