Section 20D. The district attorneys may appoint a suitable person to serve as executive director to the Massachusetts District Attorneys Association for the purpose of promoting prosecutorial resources and improving prosecutorial functions through the coordination and standardization of services and programs, together with providing information, technical assistance and educational services to ensure standardization in organization, goals, operations and procedures. The executive director may expend such funds as are appropriated therefor, together with additional funds from federal grants and other contributions that may be made available for these purposes, and may hire such professional assistants as shall be authorized. The executive director shall devote his time during ordinary business hours to his duties and shall neither directly nor indirectly engage in the practice of law.