US authorities have made an arrest in connection with pipe bombs that were planted outside the headquarters of both the Democratic and Republican parties in Washington DC on the eve of 6 January 2021, according to reports on Thursday morning.

Explosive devices were placed at night and then, on the afternoon of 6 January, the US Capitol attack occurred, when a mob of Donald Trump’s supporters stormed Congress in an effort to prevent the certification of Joe Biden’s win in the 2020 presidential election.

No one had been apprehended since a suspect placed one pipe bomb in an alley outside the Republican National Committee headquarters and put another bomb on a park bench near the Democratic National Committee headquarters, according to the FBI. A reward for pivotal information was increased in 2023 to $500,000.

On Thursday morning, Reuters, the Associated Press and CNN, each citing unnamed sources, reported that a suspect was now in custody.

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 insurrection at the US Capitol.

Videos obtained by the FBI and by the Washington Post at the time of the incidents showed a person believed to be the suspect walking through the neighborhood, wearing a gray hoodie, a mask and carrying a backpack.

The FBI noted that the suspect wore distinctive sneakers – black, gray and yellow Nike Air Max Speed Turf shoes.

The pipe bombs were rendered safe after discovery and nobody was hurt, but the FBI has said both devices could have been lethal.

The suspect was in Virginia when he was arrested on Thursday, according to a law enforcement official, and he was expected to make an initial court appearance in Washington DC, according to a source briefed on the matter.