update understanding of Federal legal rulings, court decisions, and Department policies, procedures, and guidelines related to relevant subject matters. (4) Leadership training Not later than 1 year after the date of the enactment of this subsection, the Commissioner shall develop and require training courses geared towards the development of leadership skills for mid- and senior-level career employees not later than 1 year after such employees assume duties in supervisory roles. . (b) Report Not later than 180 days after the date of the enactment of this Act, the Commissioner shall submit a report to the Committee on Finance of the Senate , the Committee on Homeland Security and Governmental Affairs of the Senate , the Committee on Homeland Security of the House of Representatives , and the Committee on Ways and Means of the House of Representatives that identifies the guidelines and curriculum established to carry out section 411(l) of the Homeland Security Act of 2002, as amended by subsection (a) of this section. (c) Assessment Not later than four years after the date of the enactment of this Act, the Comptroller General of the United States shall submit to the Committee on Homeland Security of the House of Representatives and the Committee on Homeland Security and Governmental Affairs of the Senate a report that assesses the training and education, including continuing education, required under subsection (l) of section 411 of the Homeland Security Act of 2002, as amended by subsection (a). 1145. Additional U.S. Immigration and Customs Enforcement personnel (a) Enforcement and removal officers By not later than September 30, 2021, the Director of U.S. Immigration and Customs Enforcement shall increase the number of trained, full-time, active duty U.S. Immigration and Customs Enforcement Enforcement and Removal Operations law enforcement officers performing interior immigration enforcement functions to not fewer than 8,500. (b) Homeland Security Investigations special agents By not later than September 30,