N.Y.C. Charter § 392: Section 392. Assistants.

a. The corporation counsel may appoint a first assistant corporation counsel and such other assistants as may be necessary within the appropriation therefor.

b. The first assistant corporation counsel shall, during the absence or disability of the corporation counsel, possess all the powers and perform all the duties of the corporation counsel and in case of the death or the corporation counsel or of a vacancy in that office shall act as corporation counsel until the appointment and qualification of a corporation counsel in accordance with law.

c. Any assistant shall, in addition to the duties regularly assigned to him or her, possess such of the powers and perform such of the duties of the corporation counsel as the corporation counsel shall empower such assistant to exercise by written authority filed and remaining on record in the department.