Courtney gained wide-ranging experience working in the DOJ, where she served as the U.S. government's deputy chief prosecutor in trials related to the September 11 attacks, the U.S.S. Cole bombing, and other high-profile terrorism matters. She previously served as a trial attorney in the DOJ's Counterterrorism Section, National Security Division, where she participated in and supervised some of the most significant terrorism-related investigations in the United States. Courtney advised the assistant attorney general for national security on high-level classified intelligence operations, and managed investigations with members of the intelligence community. She teamed with multiple foreign governments in domestic and foreign terrorism prosecutions and investigations. Courtney has held the highest-level security clearance, handled some of the government's most sensitive national security information for nearly 12 years, and managed the government's use and protection of national security in federal trials.
Courtney held various other positions within the DOJ's National Security Division, including with the Office of Intelligence Policy and Review, where she appeared before the Foreign Intelligence Surveillance Court (FISC) and oversaw the use of information collected under the Foreign Intelligence Surveillance Act. During her time as a prosecutor, she negotiated plea bargains with High Value Detainees (HVDs). Courtney directed prosecutions in terrorism cases related to the October 2002 Bali nightclub and U.S. consulate terrorist attacks, and the August 2003 Jakarta J.W. Marriott hotel bombing. She played a crucial role in convincing a notable terrorist co-conspirator involved in the Richard Reid "shoe bomb" plot to cooperate as a key witness for numerous terrorism trials in the Southern and Eastern Districts of New York.