5 years later, authorities arrest a suspect in Washington pipe bomb case. Here's what to know

WASHINGTON — The FBI has arrested a suspect five years after an unidentified person placed two pipe bombs outside the headquarters of the Republican and Democratic national parties in Washington.

Agents arrested Brian J. Cole Jr., 30, of Woodbridge, Virginia, on explosive charges. Calls to relatives of Cole listed in public records were not immediately returned.

The mystery behind the person's identity has bedeviled law enforcement and helped fuel conspiracy theories about Jan. 6, 2021, and the Capitol riot by a mob of President Donald Trump's supporters.

Here's what to know about the arrest:

Why now

The FBI and Justice Department declined to elaborate on what led them to the suspect. But authorities attributed the arrest to a reinvigorated investigation and a fresh analysis of already collected evidence and data.

Attorney General Pam Bondi said there was no new tip or witness that led officials to Cole. ''Just good, diligent police work and prosecutorial work,'' she said.

They struggled to determine answers to basic questions, including the person's gender and motive. They didn't know whether the act had a clear connection to the riot at the Capitol a day later, when supporters of Trump stormed the building in a bid to halt the certification of the Republicans' 2020 election loss to Democrat Joe Biden.

Pipe and kitchen timer purchases

Law enforcement officials used credit purchases of bomb-making materials, cellphone tower data and a license plate reader to zero in on Cole, according to an FBI affidavit filed in the case.

His bank account and credit card information showed he bought materials in 2019 and 2020 consistent with those used to make the pipe bombs, according to court papers. This included galvanized pipes and white kitchen-style timers, according to the affidavit. The purchases continued even after the devices were placed.

The two explosive devices found at the scenes were each roughly 1 foot (0.3 meters) long and packed with gunpowder and metal, according to two law enforcement officials familiar with the investigation.

Nike shoes

Surveillance video showed the person wearing a light sweatshirt, dark pants and sneakers, with a dark backpack slung over one shoulder. Investigators have long said the gait suggested the person was a man, but their face was obscured by a surgical mask and a hood.

Investigators focused some attention on the suspect's shoes, believed to be Nike Air Max Speed Turfs. Nike told investigators thousands of pairs had been distributed through more than two dozen retailers and so agents filed subpoenas for credit card records from Foot Locker and other chains to narrow down potential buyers.

Motive unclear

Authorities didn't disclose why they think Cole may have placed the explosives at the offices of the Democratic and Republican national committees.

Classmate called suspect ‘well-behaved and quiet'

Cole lived with his mother and other family members in a five-bedroom house on a quiet Virginia cul-de-sac about 30 miles (about 48 kilometers) south of the U.S. Capitol. He has no criminal record and was not registered to vote.

One of four children, he worked in the office of his father, a bail bondsman. His mother works as a realtor.

A high school classmate who lived in the same neighborhood and rode the bus with Cole described him as friendly but said he didn't speak much.

''He didn't stand out,'' said the classmates, who spoke on condition of anonymity out of concern for having their name associated with the suspect in a politically charged criminal case. ''As far as I remember, he was well-behaved and quiet.''

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