N.Y. Town Law § 152

§ 152. Promotion. The town board may determine that promotions of\nofficers and members of such police department shall be made by the town\nboard on the basis of seniority, meritorious police service and superior\ncapacity as shown by competitive examination, such examination to be\nconducted by the appropriate civil service commission. Individual acts\nof personal bravery may be treated as an element of meritorious service\nin such examination. The town board shall keep a complete service record\nof each member of such police department in accordance with the rules of\nthe appropriate civil service commission and shall transmit the record\nof each candidate for promotion to such civil service commission in\nadvance of such examination.\n