Can also list the CIS office where you had your interview.

It is not critical to list Director of CIS or just the office as the defendant and it does not hurt if you have more defendants -- only need to serve them once and deal with AUSA only later.

Alberto Gonzales,
United States Attorney General
US Department of Justice
950 Pennsylvania Ave., NW
Washington, DC 20530-0001

Michael Chertoff,
Secretary of the Department of Homeland Security
Office of the General Counsel
US Department of Homeland Security
Washington, DC20528

Emilio T. Gonzalez, Director of United States Citizenship and Immigration Services
Office of the Chief Counsel
U.S. Citizenship and Immigration Services (USCIS)
20 Massachusetts Ave, NW, Rm 4025
Washington, DC 20529

Robert S. Mueller, Director of Federal Bureau of Investigation
Directory of Federal Bureau of Investigation
Office of the General Counsel of the FBI
935 Pennsylvania Ave, NW
Washington, DC 20530-0001