David Mercer earned his law degree from the University of Missouri-Columbia School of Law in 1990. In law school, he was a member of the Missouri Law Review and the Order of the Barristers. He was also a quarter-finalist in the National Moot Court Competition in New York, New York. From 1990 to 1993, Mercer served as a Judicial Law Clerk in Kansas City, Missouri, for the Honorable Fernando J. Gaitan at both the Missouri Court of Appeals for the Western District of Missouri and the United States District Court for the Western District of Missouri.
From 1993 to 1995, Mercer worked for Food for the Hungry (a non-profit Christian relief and development organization) documenting, and reporting on, poverty, hunger, and refugee issues in the Third World. During this time, he lived in La Paz, Bolivia, and Kenya.
David worked extensively in Rwanda and Zaire in the months immediately following the genocidal Rwandan civil war of 1994.
David is currently the First Assistant Federal Public Defender and the Supervisor of the Springfield branch of the Office of the Federal Public Defender for the Western District of Missouri. David has been with this office since 1999, practicing exclusively federal criminal defense. David has also been an adjunct faculty member at Drury University for the last 18 years, teaching in the Legal Studies Department. For the last ten years, David has been the chairperson of that department.