Stand-ins for Vice President-elect Kamala Harris and Doug Emhoff are seen during a dress rehearsal for 59th Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Patrick Semansky/Pool via REUTERS
Officers walk back onto the inauguration stage after having been evacuated due to a potential security threat during a dress rehearsal for U.S. President-elect Joe Biden's Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Erin Schaff/Pool via REUTERS
A general view of preparations prior a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Patrick Semansky/Pool via REUTERS
People are evacuated back inside after an "external security threat" prior to a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Win McNamee/Pool via REUTERS
A military band passes the East Front of the U.S. Capitol during a dress rehearsal for U.S. President-elect Joe Biden's Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
U.S. military units march in front of the U.S. Capitol as they rehearse for U.S. President-elect Joe Biden's inauguration ceremony, in Washington, U.S., January 18, 2021. J. Scott Applewhite/Pool via REUTERS
A White House Marine sentry rehearses the arrival of President-elect Joe Biden next to a smashed window at the U.S. Capitol, in Washington, U.S., January 18, 2021. Jim Lo Scalzo/Pool via REUTERS
Members from all of the services of the US military march across in front of the White House during rehearsals ahead of President-elect Joe Biden's inauguration, in Washington, D.C., U.S., January 18, 2021. REUTER/Andrew Kelly
A general view of preparations prior to a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Jeenah Moon/Pool via REUTERS
A stand-in for U.S. President-elect Joe Biden is sworn in on the podium, as a stand-in for Jill Biden looks on during a dress rehearsal for Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Patrick Semansky/Pool via REUTERS
Members of the military take a shelter in place at the U.S. Capitol after a dress rehearsal for U.S. President-elect Joe Biden's inauguration ceremony was evacuated due to a threat, in Washington, U.S., January 18, 2021. Greg Nash/Pool via REUTERS
Chairs are set socially distanced during a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Jeenah Moon/Pool via REUTERS
A general view of rehearsal for U.S. President-elect Joe Biden's Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Erin Schaff/Pool via REUTERS
A member of the military rushes past, as people are evacuated back inside after an "external security threat" prior to a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Win McNamee/Pool via REUTERS
Stand-ins for U.S. President-elect Joe Biden and Jill Biden participate in a dress rehearsal for 59th Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Saul Loeb/Pool via REUTERSImages)
A view of preparations prior to a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Jeenah Moon/Pool via REUTERS
Stand-ins for Vice President-elect Kamala Harris, Shana Chandler, and U.S. President-elect Joe Biden, Traci Pough, wave from the bottom of the West Front steps during a dress rehearsal for 59th Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
A stand-in portraying U.S. President-elect Joe Biden rehearses the upcoming inauguration in the President's Room at the U.S. Capitol, in Washington, U.S., January 18, 2021. Jim Lo Scalzo/Pool via REUTERS
Military members run through the movements during a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Melina Mara/Pool via REUTERS
Stand-ins for President-elect Joe Biden and Jill Biden walk on the podium during a rehearsal for the 59th Presidential Inauguration at the U.S. Capitol in Washington, Monday, Jan. 18, 2021.(AP Photo/Patrick Semansky, Pool)
The National Mall is filled with a display of U.S. flags during a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Patrick Semansky/Pool via REUTERS
White House Marine sentries are seen during a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Melina Mara/Pool via REUTERS
White House Marine sentries secure the East Front door of the U.S. Capitol during an unknown external security threat, in Washington, U.S., January 18, 2021. Jim Lo Scalzo/Pool via REUTERS
The U.S. Army Band performs during a dress rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Greg Nash/Pool via REUTERS
A law Enforcement member stands guard due to a reported security threat during the rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Jeenah Moon/Pool via REUTERS
Empty seats are seen after a reported security threat during the rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Jeenah Moon/Pool via REUTERS
Members of the U.S. National Guard arrive as the U.S. Capitol goes into lockdown during the dress rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
A helicopter flies above the U.S. Capitol during the dress rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
Members of an Honor Guard walk down a set of stairs to the Capitol Visitors Center as people are evacuated indoors due to a reported security threat during the rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Caroline Brehman/Pool via REUTERS
Members of an Honor Guard evacuate the inauguration stand during a reported external security threat during the rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Caroline Brehman/Pool via REUTERS
A general view of preparations prior a dress rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Win McNamee/Pool via REUTERS
The Honour Guard arrives at the East Front of the U.S. Capitol during the dress rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
The Honour Guard arrives at the East Front of the U.S. Capitol during the dress rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
Members of the military make preparations during the rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Greg Nash/Pool via REUTERS
Military Band members dressed in costumes rehearse near the U.S. Capitol Hill, ahead of U.S. President-elect Joe Biden's inauguration, in Washington, U.S., January 18, 2021.
A general view of a rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Caroline Brehman/Pool via REUTERS
A military band passes the U.S. Capitol during the dress rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
A military band passes the U.S. Capitol during the dress rehearsal ahead of U.S. President-elect Joe Biden's inauguration in Washington, U.S., January 18, 2021. Rod Lamkey/Pool via REUTERS
A general view of a rehearsal for U.S. President-elect Joe Biden's Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 18, 2021. Caroline Brehman/Pool via REUTERS
Rehearsing Joe Biden's inauguration