The FBI are vetting all 25,000 troops from the National Guard over fears of an insider attack at the inauguration of President-elect Joe Biden.
Parts Washington DC have been turned into a fortress ahead of the inauguration on Wednesday to prevent scenes from the Capitol on January 6.
Such is the sense of threat in the US capital that authorities are even wary of the very people assigned to protect the city.
Army Secretary Ryan McCarthy said officials are conscious of the potential threat, and he warned commanders to be on the lookout within their ranks.
So far, however, he and other leaders say they have seen no evidence of any threats and officials said the vetting hadn’t flagged any issues.
”We’re continually going through the process, and taking second, third looks at every one of the individuals assigned to this operation,” McCarthy said.
He added Guard members are also getting training on how to identify potential insider threats.
Around 25,000 members of the National Guard are streaming into Washington from across the country — at least two and a half times the number for previous inaugurals.
And while the military routinely reviews service members for extremist connections, the FBI screening is in addition to any previous monitoring.
Multiple officials said the process began as the first Guard troops began deploying to DC more than a week ago.
And they said it is slated to be complete by Wednesday.
Watch Washington Correspondent Robert Moore's report from 'Fortress Washington'
“The question is, is that all of them? Are there others?” said McCarthy.
“We need to be conscious of it and we need to put all of the mechanisms in place to thoroughly vet these men and women who would support any operations like this.”
In a situation like this one, FBI vetting would involve running peoples’ names through databases and watchlists maintained by the bureau to see if anything alarming comes up.
That could include involvement in prior investigations or terrorism-related concerns, said David Gomez, a former FBI national security supervisor in Seattle.
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