What is the main responsibility of the secretary-department of Justice? In one simple sentence

The main responsibility of the Secretary of the Department of Justice is to oversee and manage the operations and policies of the department.

Policies and operations of what department

The Secretary of the Department of Justice oversees and manages the policies and operations of the Department of Justice.

The main responsibility of the Secretary of the Department of Justice is to oversee and manage the administration of the United States Department of Justice.

The main responsibility of the Secretary-Department of Justice is to provide administrative support and assist in the management and operation of the Department of Justice.