The police officers shall have the power of town grand jurors to present complaints for any offence committed against the laws of the State within the limits of said Village, and shall be entitled to receive the same fees therefor. They shall have the same power and authority as conservators of the peace within the said Village as that of town constables. They may serve any criminal process for any offence against the laws of the State committed within said Village, and may serve subpoenas for witnesses in such cases. And for all such services they shall be entitled to receive the same fees as constables are entitled to receive.