The FBI has taken a significant step forward in its nearly five-year probe into the placement of pipe bombs in Washington, D.C., just before the January 6, 2021, Capitol riot. A law enforcement official informed The Associated Press about this development.

This arrest is a pivotal moment for investigators who have been puzzled by this case for years. The incident not only fueled numerous conspiracy theories but also remained a lingering enigma following the violent events at the Capitol, a dark period in American history.

The official, who spoke under the condition of anonymity due to the ongoing nature of the case, revealed that a man was arrested Thursday morning. However, further details, including the potential charges against the suspect, have not been disclosed yet.

Criticism has also surfaced from House Republicans, who questioned the security failures that allowed the bombs to go unnoticed for 17 hours.

Last year, Dan Bongino, now the deputy director of the FBI, suggested that the incident might have been an “inside job” involving a “massive cover-up.”

Since his appointment to the FBI in March, Bongino has committed to making the pipe bomb investigation a top priority, aiming to deliver results to a skeptical far-right audience while upholding the bureau’s integrity.

We brought in new personnel to take a look at the case, we flew in police officers and detectives working as TFOs (task force officers) to review FBI work, we conducted multiple internal reviews, held countless in person and SVTC meetings with investigative team members, we dramatically increased investigative resources, and we increased the public award for information in the case to utilise crowd-sourcing leads,” he wrote in a long post on X last month.