A case diary is a record of daily investigation into a case.
Under the provision of section 172 of the code of criminal procedure, a police officer conducting the investigation is required to maintain a record of investigation done on each day in a particular case.
Section 172- Diary of proceedings in investigation says that-
(1) Every police oﬃcer making an investigation under this Chapter shall day by day enter his proceedings in the investigation in a diary, setting forth the time at which the information reached him, the time at which he began and closed his investigation, the place or places visited by him, and a statement of the circumstances ascertained through his investigation.
(1A) The statements of witnesses recorded during the course of investigation under Section 161 shall be inserted in the case diary.
(1B) The diary referred to in sub-section (1) shall be a volume and duly paginated.
(2) Any Criminal Court may send for the police diaries of a case under inquiry or trial in such Court, and may use such diaries, not as evidence in the case, but to aid it in such inquiry or trial.
(3) Neither the accused nor his agents shall be entitled to call for such diaries, nor shall he or they be entitled to see them merely because they are referred to by the Court; but, if they are used by the police oﬃcer who made them to refresh his memory, or if the Court uses them for the purpose of contradicting such police oﬃcer, the provisions of section 161 or section 145, as the case may be, of the Indian Evidence Act, 1872 (1 of 1872), shall apply.
It is a special diary different from general diary maintained by police. Every police oﬃcer making an investigation shall enter his proceedings in a diary which may be used at the trial or inquiry, not as evidence in the case but to aid the Court in such inquiry or trial. “Case diaries” are recorded under this section with the objective to enable Courts to check the method of investigation by the police. It is a document under section 91 that can be summoned by the court dehors section 172. It is utmost importance that the entries in such a diary are made with sufficient promptness, in sufficient detail, mentioning all the significant facts, in careful chronological order and with complete objectivity.
It may be noted that though the diary might be useful for getting at the means for elucidating points which need clearing up or for the discovery of relevant evidence, it can never be used as substantive evidence of any fact stated in it. The case diary is not an evidence of any date, fact or statement in the diary. A judge cannot make use of case diary in his judgement.
All police-oﬃcers-in-charge of a police station are required to keep a diary, and the Magistrate of the district is authorised to call for and inspect the same. The entire diary maintained by the police was made available to the accused by the Trial Court. The investigating oﬃcer was extensively cross-examined on many facts which were not very much relevant for purposes of the case. The Court deprecated the procedure adopted by the Trial Court. (Sidharth v State of Bihar, AIR 2005 SC 4352)
Use Of Diary
Use of diaries may be divided into three parts –
(I) Use by Court
According to section 172 (2) Any Criminal Court may send for the police diaries of a case under inquiry or trial in such Court, and may use such diaries, not as evidence in the case, but to aid it in such inquiry or trial.
(II) Use by accused or his agent
Neither the accused nor his agents shall be entitled to call for such diaries, nor shall he or they be entitled to see them merely because they are referred to by the Court. There are two exceptions – (a) if they are used by the police officer who made them to refresh his memory, or (b) if the Court uses them for the purpose of contradicting such police officer, the provisions of section 161 or section 145, as the case may be, of the Indian Evidence Act, 1872 (1 of 1872), shall apply.
(III) Use by Police officer
Police officer may use it for refreshing memory.
In this connection it is pertinent to note that court is not bound to compel the police witness to look at the diary in order to refresh the memory nor is the accused entitled to insist that he should do so.
Shamshul kanwar v. state of UP 1995, in this case supreme court opined that a legislative change is necessary providing for framing of appropriate and uniform regulations regarding the maintenance of diaries by the police for the purpose contemplated by section 172 vis-à-vis the other sections such as section 167.
In case the case diary is not maintained as required by section 172, that in itself may not vitiate the trial: but it would expose the evidence of the investigating police officer to adverse criticism, and might diminish the value of his evidence.
Case diary is a special diary to be maintained by every investigating police officer required to enter everyday proceedings in the investigation. It cannot be maintained by anyone else. It is utmost importance that the entries in such a diary are made with sufficient promptness, in sufficient detail.
(Author: Palak Jain, pursuing LLB from Faculty of law, Delhi University.)