N.Y.C. Admin. Code § 7-109: § 7-109 Corporation counsel; when the corporation counsel may appear for officer, subordinate, or employee of an agency.

The corporation counsel, in his or her discretion may appear, or direct any of his or her assistants to appear, in any action or proceeding, whether criminal or civil, which may be brought against any officer, subordinate or employee in the service of the city, or of any of the counties contained therein, by reason of any acts done or omitted by such officer, subordinate or employee, while in the performance of his or her duty, whenever such appearance is requested by the head of the agency in which such officer, subordinate or employee is employed or whenever the interests of the city require the appearance of the corporation counsel. The head of the agency in which such officer, subordinate or employee is employed shall submit all pertinent papers and other documents to the corporation counsel.