This bill, titled the Gang Activity Reporting Act of 2025, amends title 28 of the United States Code to establish a new requirement for the Attorney General. It mandates that the Attorney General, in collaboration with the Secretary of Homeland Security and the Director of the Federal Bureau of Investigation, submit an annual report to the Judiciary Committees of both the Senate and the House of Representatives. This report, due 150 days after enactment and then by the end of each fiscal year, aims to provide current and accurate data on gang activity, reporting, investigation, and prosecution. The comprehensive report must detail various aspects of gang activity, including the growth of local, national, and transnational gangs over the preceding 10 fiscal years, with specific numerical data and trends in membership and activities. It also requires information on the tools and methods gangs use to commit crimes, the extent of their cooperation, and an assessment of state-based reporting issues affecting federal data collection. Furthermore, the report must outline federal initiatives undertaken by the Department of Justice, Department of Homeland Security, and FBI to track, investigate, and prosecute gang-related unlawful activity, along with allocated resources and gang enforcement statistics, including arrests and firearms seized.