The House Oversight and Judiciary Committees held a joint hearing Thursday with former top FBI counterintelligence investigator Peter Strzok, the writer of hundreds of controversial text messages displaying a strong anti-Trump bias during the time when the FBI was investigating possible links between the Trump campaign and Russia. Strzok expressed regret at the "confusion" and "pain" the disclosure of his text messages caused to his loved ones. "Certain private messages of mine have provided ammunition for misguided attacks on the FBI, an institution I love deeply and have served proudly for over 20 years." "Like many people, I had an expressed personal political opinions during an extraordinary presidential election," he said. "Opinions that were not always expressed in terms I am proud of." "Having worked in national security for two decades and proudly served in the US Army those opinions were expressed out of deep patriotism and an unyielding belief in our great American democracy," Strzok said about the messages. "At times my criticism was blunt, but despite how it has been characterized it was not limited to one person or one party." "Let me be clear, unequivocally and under oath," he said. "Not once in my 26 years of defending our nation did my personal opinions impact any official action I took." More: <iframe width="560" height="315" src="https://www.youtube.com/embed/kznBrrwMHmo" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>