In a cognisable case:

S. 175. Police officer's power to investigate cognizable case. (1) Any officer in charge of a police station may, without the order of a Magistrate, investigate any cognizable case which a Court having jurisdiction over the local area within the limits of such station would have power to inquire into or try under the provisions of Chapter XIV: Provided that considering the nature and gravity of the offence, the Superintendent of Police may either himself investigate or require the Deputy Superintendent of Police to investigate the offence.