The FBI has made an arrest in its nearly 5-year-old investigation into who placed pipe bombs in Washington on the eve of the Jan. 6, 2021, riot at the US Capitol.

The arrest marks the first time investigators have settled on a suspect in an act that had long vexed law enforcement, spawned a multitude of conspiracy theories and remained an enduring mystery in the shadow of the chapter of American history.

The arrest took place this morning, and the suspect has been identified as Brian Cole from Virginia. He was arrested in Virginia, according to another person familiar with the matter. No other details are immediately available, including the charges the man might face.

The pipe bombs were placed on the evening of Jan. 5, 2021, near the offices of the Democratic and Republican national committees in the District of Columbia. Nobody was hurt before the bombs were rendered safe, but the FBI has said both devices could have been lethal.

In the years since, investigators have sought the public’s help in identifying a shadowy subject seen on surveillance camera even as they struggled to determine answers to basic questions, including the person’s gender and motive and whether the act had a clear connection to the riot at the Capitol a day later when supporters of President Trump stormed the building in a bid to halt the certification of the Republican’s 2020 election loss to Democrat Joe Biden.

Seeking a breakthrough, the FBI last January publicized additional information about the investigation, including an estimate that the suspect was about 5-foot-7, as well as previously unreleased video of the suspect placing one of the bombs.

The bureau had for years struggled to pinpoint a suspect despite hundreds of tips, a review of tens of thousands of video files and a significant number of interviews.

(AP)