New York Consolidated Laws, Legislative Law - LEG § 2. Exemption of members and officers from arrest

A member of the legislature shall be privileged from arrest in a civil action or proceeding other than for a forfeiture or breach of trust in public office or employment, while attending upon its session, and for fourteen days before and after each session, or while absent for not more than fourteen days during the session with the leave of the house of which he is a member.

An officer of either house shall be privileged from arrest in such a civil action or proceeding while in actual attendance upon the house.  Either house shall have the power to discharge from arrest any of its members or officers arrested in violation of his privilege from arrest.