Whenever a vacancy occurs in the office of a full-time district court judge the successor shall be elected for a full term of six years and upon qualification shall enter at once upon the discharge of the duties of his office. But subject to the provisions of § 16.1-69.9:3, the judges of the circuit having jurisdiction over the district shall have the power while the General Assembly is not in session to fill pro tempore vacancies in the office of full-time district court judges. No person shall be appointed under this section until he has submitted his fingerprints to be used for the conduct of a national criminal history record search and a Virginia criminal history record search, submitted to a search of the central registry maintained pursuant to § 63.2-1515 for any founded complaint of child abuse or neglect, and provided a written statement of economic interests on the disclosure form prescribed in § 2.2-3117. No person with a criminal conviction for a felony shall be appointed as a pro tempore judge. Appointment to every such vacancy shall be by commission to expire at the end of thirty days after the commencement of the next session of the General Assembly.