Capitol Police Advancement Act of 2020 This bill establishes reporting duties for the U.S. Capitol Police (USCP), provides a separate budget allocation for the USCP Office of Inspector General (OIG), and revises the rules for termination of a USCP officer, member, or employee. Specifically, the bill requires the USCP to submit a biannual report on its functions and activities and to provide, upon request from the Bureau of Justice Statistics, certain information, data, and reports. The bill also requires the USCP to include the annual budget request of its OIG in the USCP budget without change. Further, the bill requires Congress to provide a separate allocation, within the amounts made available for salaries and expenses of the USCP, for the salaries and expenses of the OIG. The OIG must make each of its reports publicly available. In addition, the bill provides that an approval by the Capitol Police Board of the termination of an officer, member, or employee of the USCP shall be final and may not be reviewed or appealed. Under current law, the USCP may not terminate an officer, member, or employee until it has notified both the individual and the Capitol Police Board, and the board has approved the termination.