S. Rept. 117-31: Reporting Efficiently to Proper Officials in Response to Terrorism Act of 2021, Report to Accompany S. 517, Including Cost Estimate of the Congressional Budget Office, July 26, 2021 [open pdf - 401KB]
From the Purpose and Summary: "The purpose of S. 517, the Reporting Efficiently to Proper Officials in Response to Terrorism Act of 2021, or REPORT Act, is to require agencies to submit to Congress an unclassified report on each act of terrorism that occurs in the United States within a year of the conclusion of the investigation into the act. [...] The report must include the facts of the act of terrorism, identified national security gaps that require correction to prevent similar future acts of terrorism, and recommendations for new measures that could strengthen homeland security. A public summary of the report must also accompany the more detailed report for Congress."
S. Rept. 117-31; Senate Report 117-31
U.S. Government Publishing Office: http://www.gpo.gov/