Section 5 of the Criminal Procedure Code shows that all offences “shall be investigated, inquired into, tried and otherwise dealt with in accordance with the Code”. For the purposes of investigation offences are divided into two categories ‘cognizable‘ and ‘non-cognizable’.

Cognizable offences, are serious offences, and non-cognizable offences are less serious offences and generally bailable.

When information of the commission of a cognizable offence is received or such commission is suspected, the appropriate police officer has the authority to enter on the investigation of the same (unless it appears to him that there is no sufficient ground). But where the information relates to a non-cognizable offence, he shall not investigate it without the order of a competent Magistrate.

Thus it may be seen that according to the scheme of the Code, investigation is a normal preliminary to an accused being put up for trial for a cognizable offence (except when the Magistrate takes cognizance otherwise than on a police report in which case he has the power under section 202 of the Code to order investigation if he thinks fit).

Start of an Investigation

Investigation usually starts on information relating to the commission of an offence given to an officer in charge of a police station and recorded under section 154 of the Code.

  • If from information so received or otherwise, the officer in charge of the police station has reason to suspect the commission of an offence, he or some other subordinate officer deputed by him, has to proceed to the spot to investigate the facts and circumstances of the case and if necessary to take measures for the discovery and arrest of the offender.
  • Thus investigation primarily consists in the ascertainment of the facts and circumstances of the case. By definition, it includes “all the proceedings under the Code for the collection of evidence conducted by a police officer”.
  • For the above purposes, the investigating officer is given the power to require before himself the attendance of any person appearing to be acquainted with the circumstances of the case.
  • He has also the authority to examine such person orally either by himself or by a duly authorised deputy.
  • The officer examining any person in the course of investigation may reduce his statement into writing and such writing is available, in the trial that may follow, for use in the manner provided in this behalf in section 162.
  • Under section 155 the officer in charge of a police station has the power of making a search in any place for the seizure of anything believed to be -necessary for the purpose of the investigation. The search has to be conducted by such officer in person. A subordinate officer may be deputed by him for the purpose only for reasons to be recorded in writing if he is unable to conduct the search in person and there is no other competent officer available.
  • The investigating officer has also the power to arrest the person or persons suspected of the commission of the offence under section 54 of the Code.
  • A police officer making an investigation is enjoined to enter his proceedings in a diary from day-to-day. Where such investigation cannot be completed within the period of 24 hours and the accused is in custody he is enjoined also to send a copy of the entries in the diary to the Magistrate concerned.
  • It is important to notice that where the investigation is conducted not by the officer in charge of the police station but by a subordinate officer (by virtue of one or other of the provisions enabling him to depute such subordinate officer for any of the steps in the investigation) such subordinate officer is to report the result of the investigation to the officer in charge of the police station.
  • If, upon the completion of the investigation it appears to the officer in charge of the police station that there is no sufficient evidence or reasonable ground, he may decide to release the suspected accused, if in custody, on his executing a bond. If, however, it appears to him that there is sufficient evidence or reasonable ground, to place the accused on trial, he is to take the necessary steps therefore under section 170 of the Code.

In either case, on the completion of the investigation he has to submit a report to the Magistrate under section 173 of the Code in the prescribed form furnishing various details. Thus, under the Code investigation consists generally of the following steps:

(1) Proceeding to the spot,

(2) Ascertainment of the facts and circumstances of the case,

(3) Discovery and arrest of the suspected offender,

(4) Collection of evidence relating to the commission of the offence which may consist of;

(a) the examination of various persons (including the accused) and the reduction of their statements into writing, if the officer thinks fit,

(b) the search of places of seizure of things considered necessary for the investigation and to be produced at the trial, and

(5) Formation of the opinion as to whether on the material collected there is a case to place the accused before a Magistrate for trial and if so taking the necessary steps for the same by the filing of a charge-sheet under section 173.

Deputation of subordinate officer

The scheme of the Code also shows that while it is permissible for an officer in charge of a police station to depute some subordinate officer to conduct some of these steps in the investigation, the responsibility for every one of these steps is that of the person in the situation of the officer in charge of the police station, it having been clearly provided in section 168 that when a subordinate officer makes an investigation he should report the result to the officer in charge of the police station.

It is also clear that the final step in the investigation, viz. the formation of the opinion as to whether or not there is a case to place the accused on trial is to be that of the officer in charge of the police station. There is no provision permitting delegation thereof but only a provision entitling superior officers to supervise or participate under section 551.

When such a statutory provision enjoins that the investigation shall be made by a police officer of not less than a certain rank, unless specifically empowered by a Magistrate in that behalf, notwithstanding anything to the contrary in the Code of Criminal Procedure, it is clearly implicit therein that the investigation (in the absence of such permission) should be conducted by the officer of the appropriate rank.

This is not to say that every one of the steps in the investigation has to be done by him in person or that he cannot take the assistance of deputies to the extent permitted by the Code to an officer in charge of a police station conducting an investigation or that he is bound to go through each of these steps in every case. When the Legislature has enacted in emphatic terms such a provision it is clear that it had a definite policy behind it. To appreciate that policy, it is relevant to observe that under the Code of Criminal Procedure most of the offences relating to public servants as such, are non-cognizable.