The suspect has been charged with placing the bombs, which did not detonate. The allegations, if proven, would end a longstanding mystery that sparked a multitude of conspiracy theories over who planted the pipe bombs before a mob of pro-Trump supporters stormed the Capitol aiming to stop Joe Biden from being installed as president.  Authorities have not yet determined a motive, a law enforcement official said. But the suspect has been linked to statements in support of anarchist ideology, said two people briefed on the arrest.

The FBI’s case against the suspect is not based on a new breakthrough, according to two sources, but instead on a review the FBI conducted in recent weeks of evidence that had already been gathered and which the department had in its possession. The sources requested anonymity to speak freely about a sensitive case. That voluminous trove of material was largely collected in 2021 and 2022.