FBI vetting Guard troops in DC amid fears of insider attack

National Guard walk near the Capitol as security is increased ahead of the inauguration of President-elect Joe Biden and Vice President-elect Kamala Harris, Sunday, Jan. 17, 2021, in Washington. (AP Photo/Julio Cortez)

National Guard troops reinforce security around the U.S. Capitol ahead of the inauguration of President-elect Joe Biden and Vice President-elect Kamala Harris, Sunday, Jan. 17, 2021, in Washington. (AP Photo/J. Scott Applewhite)

National Guard troops reinforce security around the U.S. Capitol ahead of expected protests on Sunday leading up to President-elect Joe Biden’s inauguration in Washington on Wednesday. (AP Photo/J. Scott Applewhite)

WASHINGTON — U.S. defense officials say they are worried about an insider attack or other threat from service members involved in securing President-elect Joe Biden’s inauguration, prompting the FBI to vet all of the 25,000 National Guard troops coming into Washington for the event.