For seven months, FBI agent Peter Strzok has been the target of harsh criticism from President Donald Trump and congressional Republicans over his role in investigations into Russian election meddling. On Thursday, Strzok got a chance to speak publicly for the first time, defending himself forcefully and harshly criticizing his own investigators. Testifying publicly in a House Oversight Committee hearing, Strzok argued that Trump’s regular insinuations that he was part of a “deep state” effort to harm his candidacy are wrong, noting that there are procedures in place to prevent any single agent from affecting an investigation. “The suggestion that I’m in some dark chamber somewhere in the FBI would somehow cast aside all of these procedures, all of these safeguards, and somehow be able to do this is astounding to me — it simply couldn’t happen,” he said. Here’s what you need to know about Strzok and the hearing. Who is Peter Strzok? Strzok was a lead agent on both the investigation into Hillary Clinton’s email server and served on Special Counsel Robert Mueller’s investigation into Russian meddling in the 2016 election.