Oklahoma City, Oklahoma – Mark A. Yancey has accepted a Department of Justice position at the National Advocacy Center in Columbia, South Carolina, and has therefore announced his resignation as United States Attorney for the Western District of Oklahoma.  First Assistant U.S. Attorney  Robert J. Troester will become Acting U.S. Attorney at midnight on Saturday, January 20.

U.S. Attorney Yancey joined the office in 1991, after having served as a Special Agent with the FBI.  He has prosecuted many cases and served in many roles, including as First Assistant U.S. Attorney and Criminal Chief under U.S. Attorney Sanford C. Coats from January 2010 until January 2016.  He became Acting U.S. Attorney upon Mr. Coats’s resignation and was later appointed U.S. Attorney by the Attorney General and then by the district judges of the Western District of Oklahoma.  During his tenure as U.S. Attorney, he has served on three sub-committees of the Attorney General’s Advisory Counsel—those concerning national security, civil rights, and Native American issues.

On January 22, Mr. Yancey will take up the position of Assistant Director at the National Advocacy Center, where he will coordinate training for federal prosecutors in national security and other criminal cases.

Upon Mr. Yancey’s resignation, First Assistant U.S. Attorney Troester will become Acting U.S. Attorney by operation of law under the Vacancies Reform Act of 1998.  Like U.S. Attorney Yancey, First Assistant Troester has served the Department of Justice for many years.  He became an Assistant U.S. Attorney in September 1995, after several years in private practice in Oklahoma City.  As an Assistant United States Attorney, Troester has held various supervisory positions, including Civil Chief, Executive Assistant U.S. Attorney, First Assistant U.S. Attorney, and Acting U.S. Attorney on two prior occasions.  Troester has also served on detail assignments within the Department of Justice in Washington D.C. as a Deputy Director in the Executive Office for United States Attorneys and, since April 2017, he has served as an Associate Deputy Attorney General and Senior Counsel to Deputy Attorney General Rod Rosenstein. 

"I would like to thank Mr. Yancey for his two years of service in the challenging position of U.S. Attorney," said Mr. Troester.  "He has demonstrated steady leadership for the talented prosecutors and civil litigators who are working to protect fellow citizens from crime and to further the interests of the United States.  The task of continuing that leadership humbles me, but I look forward to working with federal, state, and tribal authorities for the common good, particularly on this Administration’s efforts to reduce violent crime."