Section 155 of the Code of Criminal Procedure deals with information relating to non-cognizable cases, and it is provided that when information is given to an Officer-in-charge of a Police Station about the commission of a non-cognizable offence, he must enter the substance of the information in a book to be kept in the prescribed form, and refer the informant to the Magistrate.
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It is important to note that no Police Officer can investigate a non- cognizable case without the order of a Magistrate. If the Police Officer receives the Magistrate’s order, he can exercise the same powers of investigation as he can exercise in the case of a cognizable offence.
Moreover, if one case relates to two or more offences, of which at least one is cognizable, the case is to be deemed to be a cognizable case, despite the fact that the other offences are non-cognizable.
The Supreme Court has held that whilst investigating a cognizable offence and presenting a charge-sheet for it, the Police are not debarred from investigating any non-cognizable offence arising out of the same facts, and including them in their final report. (Pravin Chandra, — A.I.R. 1985 S.C. 1185)
As far as cognizable offences are concerned, any Officer-in-charge of a Police Station is empowered, without any order of the Magistrate, to investigate any cognizable case, which a Court having jurisdiction over that local area would have power to inquire into.
In such cases, the Police Officer must also send a Report of his investigation to a Magistrate and also himself proceed, or depute one of this Subordinate Officers to proceed, to the spot, to investigate the facts and circumstances, and if necessary, to take steps for the discovery and arrest of the offender. If, however, no sufficient ground for making an investigation exists, the Officer-in-charge of the Police Station need not investigate the case.
The Supreme Court has held that the duty of the investigating Officer is not merely to bolster up a prosecution case with such evidence as may enable the Court to record a conviction, but to bring out the real unvarnished truth. (Jamuna,—A.I.R. 1974 S.C. 1822)
It has also been held that an investigation by the Head Constable, who was the person to whom the offer of bribe was alleged to have been made, and who lodged the F.I.R. against the accused, is not proper. (Bhagwan Singh, — 1975 S.C.C. 737)
On receiving the report, as stated above, the Magistrate can direct an investigation into the case, or alternatively proceed to hold a preliminary inquiry into the case or depute any Subordinate Magistrate to do so.