A suspect who allegedly planted pipe bombs blocks from the U.S. Capitol on January 5, 2021, is now in federal custody after a nearly five-year investigation, law enforcement sources told Fox News Digital on Thursday.

The FBI arrested the suspect, a male living in Virginia, early Thursday morning, the sources said. The man in custody is 30-year-old Brian Cole Jr. of Woodbridge, two sources said.

Authorities discovered the two pipe bombs near the Republican and Democratic National Committees’ headquarters around the same time that thousands of protesters a few blocks away began to descend on the Capitol over the 2020 election results.

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Video footage released by the FBI showed an unidentified person placing the pipe bombs near the two headquarters more than 16 hours before law enforcement found them.

The suspect was seen wearing a gray hoodie, Nike Air Max Speed Turf sneakers, a mask, glasses and gloves, but the person’s identity had long been unknown.

The initial investigation had slowed in under two months, by the end of February 2021, a possible result of credible leads drying up at the time, according to a congressional report.

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The lingering mystery led a faction of President Donald Trump’s base to raise concerns about the timing of the pipe bomb incident and security failures surrounding it. Some elevated theories that the Biden administration was not forthright to the public about the facts of the case.

FBI Deputy Director Dan Bongino had suggested the planting of the bombs was an “inside job” prior to joining the bureau. In May, he told Fox News authorities were “closing in” on suspects.

This is a developing story. Check back for updates.

Fox News’ Bill Melugin contributed to this report.