Section 172 of the Cr.P.C deals with the provisions of the case diary. In this regard section 172(1) provides that 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.
l Thus section 172(1) Cr.P.C. directs the investigation officer to keep a diary and enter the proceedings of the investigation. This diary is called as case diary or "special diary" or Police Diary or a Station House Report. Investigating officer is directed to mention in such diary 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. The statements of witnesses recorded during the course of investigation under Section 161 [ 172(1A)]. Also, such diary shall be a volume and duly paginated [ 172(1B)].
l As far as object of the Case diary is concerned, it was held in the case Queen-Empress v. Mannu, that the object of this section is to enable the Magistrate to know what the day-to-day information available to the investigating police officer of the case and what were the lines of his investigation. The object of maintaining a case diary is to enable the court to check the method of investigation by the police. Further, in cases Bhagwant Singh v. Commr. of Police, Delhi, (1983) 3 SCC 344: and Kehar Singh v. State (Delhi Admn.), (1988) 3 SCC 609, it was held that it is of utmost importance that the entries in such a diary are made with sufficient promptness, in sufficient detail, mentioning all significant facts, in careful chronological order and with complete objectivity. The haphazard maintenance of the diary would defeat the very purpose for which it is required to be maintained. In cases Zahiruddin v. Emperor, AIR 1947 PC 75: and Niranjan Singh v. State of UP., AIR 1957 SC 142: it has been held that If 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.
l As far as use of the Case diary is concerned, it is dealt by section 172(2) and 172(3) Cr.P.C read with sections 145, 159 and 161 of the Indian Evidence Act. As per these provisions, case diary can be used by the Criminal Court, Investigating officer and the accused within the permissible limits of these sections.
l 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. In this regard, in case Habeeb Mohammad v. State of Hyderabad, AIR 1954 SC 51, 60: the Supreme Court has held that the police diary of a case under inquiry or trial can be made use of by criminal court only for aiding it in such inquiry or trial. This diary cannot be used as evidence of any date, fact or statement contained therein. Further, in case of A.K. Roy v. State of West Bengal, it was held that the Magistrate cannot take cognizance or issue process against the accused on the material contained in the case diary alone unless the fact contained in the report under section 173 of this Code constitute the offence.
Further, investigating officer ie maker of the case diary can use it for refreshing his memory under section 159 of the Indian Evidence Act.
l Also, case diary can be used by the accused in accordance of section 172(3) Cr.P.C. which provides that 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. Thus, Section 172(3) imposes a restriction on the use of case diary by the accused person. The case diary or special Diary, including every entry in it, is absolutely privileged from inspection by the accused or by his pleader. The reason of this restriction is that if the accused were entitled to see the case diary, the investigating police officer might not record matters injurious to the prosecution. In the absence of such a restriction on the accused person, the informer conveying information to the police would be deterred and that would hamper speedy investigation.
l Section 172(3) Cr.P.C. further provides that, “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 means, that the accused person is allowed to use the case diary for cross-examination of the police officer who made it under two circumstances:
1. If the police officer, while giving evidence, refreshes his memory by referring to the case diary (and this is permissible under Section 159 of the Evidence Act). In that case, the accused is entitled to see the relevant entries in the diary and may use the same for cross-examining the police officer as provided by Section 161 of the Evidence Act; or
2. if the Court uses the diary for the purpose of contradicting such police officer in accordance with the provisions of Section 145 of the Evidence Act, then the accused can have the right to inspect the relevant portions of the diary may use the same for cross-examining the police officer as provided by Section 161 of the Evidence Act;
l Thus, case diary can be used by the Criminal Court, investigating officer and accused withi permissible limits as discussed above.