On January 6, 2021, William J. Walker was head of the D.C. National Guard. He had buses full of guardsmen in riot gear ready to deploy in case Donald Trump’s “Stop the Steal” rally turned dangerous. But when rioters violently stormed the Capitol building, the Guard was nowhere to be found. Walker says he was forced to wait for three hours before his superiors allowed him to send in his troops. “My soldiers were asking me, ‘Sir, what the hell is going on?’” Walker says. “‘Are they watching the news? Are they watching what’s going on at the Capitol?’ And I had no answer. I don’t recall ever being in that position, where I did not have an answer for my soldiers.”

Now, almost one year later, Walker is the sergeant-at-arms of the U.S. House of Representatives—the first Black man to ever hold that office. The Experiment’s correspondent Tracie Hunte and producer Peter Bresnan visit Walker in his new office at the Capitol to ask him about what happened on January 6, and what he’s doing to make sure it never happens again.

Further reading: “The Man Who Could Have Stopped an Insurrection,” “Trump’s Next Coup Has Already Begun,” “Are We Doomed?,” and “What the GOP Does to Its Own Dissenters”

A transcript of this episode is available.

Be part of The Experiment. Use the hashtag #TheExperimentPodcast, or write to us at theexperiment@theatlantic.com.

This episode was produced by Tracie Hunte and Peter Bresnan with help from Alina Kulman. Editing by Emily Botein and Jenny Lawton with help from Julia Longoria. Fact-check by William Brennan. Sound design by David Herman with additional engineering by Joe Plourde. Transcription by Caleb Codding.

Music by Keyboard (“Over the Moon,” “Water Decanter,” “Mu,” and “Small Island”), Arabian Prince in a UK World (“The Feeling of Being on a Diet”), Water Feature (“Ancient Morsel”), Laundry (“Laundry”), and Column (“Aerolove”) provided by Tasty Morsels. Additional audio from span.org/video/?509313-1/senate-rules-homeland-security-committees-hearing-us-capitol-attack&live=">C-SPAN, The Untouchables, the FBI, and Forbes.