Criminal Investigation
Learning Objectives
By the end of this page you should be able to:
- State the statutory stages of investigation under Chapter XII CrPC, from FIR registration to the final report under Section 173
- Explain why Lalita Kumari v. Govt. of NCT of Delhi (2014) made FIR registration mandatory for cognizable offences
- Apply Sections 156-157 CrPC to determine when police may investigate without a magistrate's order
- Distinguish a statement recorded under Section 161 from one recorded under Section 164
- Analyse the evidentiary value and limits of a case diary maintained under Section 172
- Identify the safeguards that apply to search and seizure under Section 165 CrPC
Quick Answer
Criminal investigation is the fact-finding stage of a criminal case — the process by which police gather evidence to establish whether a crime occurred and who is responsible, before the matter goes to trial. In India, it is governed by Chapter XII of the CrPC 1973 (the corresponding provisions now sit in the Bharatiya Nagarik Suraksha Sanhita, 2023, or BNSS, which has replaced the CrPC as the current law). It begins with registration of an FIR under Section 154 for a cognizable offence, followed by police powers to examine witnesses, search premises, and seize evidence, and ends with a final report (chargesheet) under Section 173 that either sends the accused for trial or closes the case. Investigation matters because it is where evidence is created and preserved — a flawed investigation can collapse an otherwise valid prosecution at trial.
Core Concepts
1. Registration of the First Information Report (FIR)
Definition: An FIR is the information relating to the commission of a cognizable offence, reduced to writing by the officer in charge of a police station under Section 154 CrPC (Section 173 BNSS), which sets the investigative machinery in motion.
Explanation: Section 154(1) requires that any information about a cognizable offence, given orally or in writing, be recorded, read over to the informant, and signed by them. A copy must be given to the informant free of cost. If the officer refuses to register the FIR, the aggrieved person can send the substance of the information in writing to the Superintendent of Police under Section 154(3), who must then investigate or direct investigation.
Example: A shopkeeper reports a theft at the local police station. The duty officer records the complaint verbatim, reads it back to the shopkeeper to confirm accuracy, and both sign the FIR register entry — this is the FIR.
Real-World Example: In practice, victims of offences like dowry harassment or cybercrime have historically faced resistance from police reluctant to register an FIR because it commits the station to investigate and report statistics. This resistance is precisely what Lalita Kumari was meant to eliminate.
Why It Matters: The FIR is not evidence of the truth of its contents, but it fixes the earliest version of events, starts the limitation clock for certain procedural safeguards, and triggers the accused's right to move for anticipatory bail. A delayed or manipulated FIR is a common ground of attack by the defence at trial.
Common Misunderstanding: Students often think police have discretion whether to register an FIR for a cognizable offence. They do not. In Lalita Kumari v. Govt. of NCT of Delhi (2014), a five-judge Constitution Bench held that registration of an FIR is mandatory under Section 154(1) if the information discloses a cognizable offence, and no preliminary inquiry is permitted before registration in such cases. A preliminary inquiry is permissible only in a narrow set of categories — matrimonial/family disputes, commercial disputes, corruption cases, medical negligence, and cases with abnormal delay — and even then must be completed within a limited period (generally 7 to 15 days) and must be recorded.
2. Investigative Powers of the Police
Definition: Sections 156 and 157 CrPC empower the officer in charge of a police station to investigate a cognizable case without the order of a Magistrate, and lay down the procedure for commencing that investigation.
Explanation: Under Section 156(1), a police officer in charge of a station has power to investigate any cognizable case without needing prior judicial authorisation — this is what distinguishes cognizable from non-cognizable offences. Section 157 requires that, on receiving information of a cognizable offence, the officer must forthwith send a report to the Magistrate empowered to take cognizance and proceed to the spot to investigate the facts, arrange for evidence collection, and if necessary, arrest the offender. Section 156(3) additionally allows a Magistrate to direct the police to register an FIR and investigate, if a complainant has been refused registration.
Example: A resident reports a robbery. Because robbery is a cognizable offence, the local police station can begin investigating immediately — visiting the scene, questioning witnesses, and collecting evidence — without first getting a Magistrate's permission.
Real-World Example: Where police refuse to register an FIR despite a cognizable offence being disclosed, an aggrieved person routinely approaches the jurisdictional Magistrate under Section 156(3), who can direct the police to register the case and investigate — this is a common remedy used in India when local police are uncooperative, particularly in cases against influential persons.
Why It Matters: These sections mark the functional difference between cognizable and non-cognizable offences, and they define how quickly and independently police can act to preserve a crime scene and evidence before it degrades or is tampered with.
Common Misunderstanding: Students often assume any complaint automatically triggers a police-led investigation. In fact, for non-cognizable offences, police cannot investigate without the Magistrate's order under Section 155(2) — they can only record the information in a non-cognizable (NC) register and refer the complainant to the Magistrate.
3. Examination of Witnesses (Sections 161 and 164)
Definition: Section 161 CrPC empowers a police officer investigating a case to orally examine any person acquainted with the facts, while Section 164 empowers a Magistrate to record statements and confessions during the course of investigation.
Explanation: Under Section 161, the investigating officer may reduce the witness's statement to writing, but the witness is not required to sign it (Section 162), and the statement generally cannot be used as substantive evidence at trial — it can only be used to contradict the witness under Section 145 of the Evidence Act, or to corroborate a prosecution witness in limited circumstances under Section 157 of the Evidence Act. Section 164 statements, by contrast, are recorded by a Magistrate, who must first explain to the person making the statement that they are not bound to make it and that anything they say may be used against them. Confessions under Section 164 carry a much higher degree of reliability and can be used as substantive evidence, subject to safeguards against coercion.
Example: During a murder investigation, the investigating officer records a neighbour's account of what they saw (a Section 161 statement). Separately, a co-accused who wants to confess is produced before the Magistrate, who explains the consequences and records the confession under Section 164.
Real-World Example: In sexual assault investigations, courts increasingly encourage recording the survivor's statement under Section 164 (rather than relying only on the Section 161 statement to police) precisely because it carries greater evidentiary weight and cannot easily be retracted or manipulated later — it is recorded by a neutral judicial officer, not the investigating police.
Why It Matters: The distinction determines what a defence lawyer can and cannot do with a statement at trial. A Section 161 statement is a valuable tool for cross-examining a witness who changes their story, but it is not proof of the facts stated. A Section 164 statement or confession can, subject to safeguards, form the basis of conviction.
Common Misunderstanding: A common student error is treating a Section 161 statement as if it were sworn testimony. It is neither signed by the witness nor given under oath, and Section 162 CrPC expressly bars its use as substantive evidence — its only real courtroom use is impeachment through prior inconsistent statement.
4. Search, Seizure, and the Case Diary
Definition: Section 165 CrPC empowers an investigating officer to search a place without a warrant if there is reasonable ground to believe that something necessary for the investigation may be found there and that a warrant cannot be obtained without undue delay; Section 172 requires the officer to maintain a case diary recording the day-to-day progress of the investigation.
Explanation: Before conducting a warrantless search under Section 165, the officer must record in writing the grounds of belief and the specific thing to be searched for, and must, so far as practicable, conduct the search in person. Section 100 lays down general safeguards for searches — the presence of two independent witnesses ("panchas") and preparation of a seizure memo/panchnama. The case diary under Section 172 is a day-by-day record of the investigation's progress — statements recorded, places visited, evidence gathered — maintained by the investigating officer for the court's reference, though it is not evidence itself and the accused has no automatic right to access it (only the court may use it to aid the trial, and the accused may use it only if the officer refers to it to refresh memory).
Example: Investigating a burglary, an officer has credible information that stolen goods are stored at a specific house and fears the goods will be moved before a warrant can be obtained. Under Section 165, the officer records the grounds in writing and conducts the search immediately, with two independent witnesses present, and prepares a seizure memo listing the recovered items.
Real-World Example: In narcotics cases under the NDPS Act, courts are extremely strict about compliance with search-and-seizure safeguards; failure to follow the panchnama and independent-witness requirements is one of the most common reasons NDPS convictions are overturned on appeal.
Why It Matters: Search and seizure is where police power directly collides with a citizen's right to privacy and property. Strict procedural compliance is what makes seized evidence admissible and credible in court — sloppy searches routinely destroy otherwise strong cases.
Common Misunderstanding: Many assume the case diary can be used by the defence to cross-examine the investigating officer freely. Under Section 172(3), the accused does not have a right to call for or use the case diary merely because it exists — access is restricted to the court, and to the accused only in the narrow situation where the officer uses it to refresh their memory or the court uses it to contradict the officer.
Visual Learning
Key Terms
| Term | Definition | Related Concept |
|---|---|---|
| FIR (First Information Report) | Written record of information about a cognizable offence, made under Section 154 | Section 154, Lalita Kumari |
| Cognizable Offence | Offence for which police may investigate and arrest without prior judicial order | Sections 154, 156 |
| Non-Cognizable Offence | Offence for which police need a Magistrate's order to investigate | Section 155 |
| Investigation | The stage of collecting evidence by police before trial | Chapter XII CrPC |
| Inquiry | Judicial proceeding, other than trial, conducted by a Magistrate or court | Section 2(g) CrPC |
| Section 161 Statement | Unsigned witness statement recorded by police during investigation | Section 162, Evidence Act S.145 |
| Section 164 Statement | Statement or confession recorded by a Magistrate during investigation | Judicial safeguards, confession |
| Case Diary | Day-to-day record of investigation progress maintained by the investigating officer | Section 172 |
| Panchnama | Memo of search/seizure prepared in presence of independent witnesses | Section 100, Section 165 |
| Final Report / Chargesheet | Report filed under Section 173 summarising evidence and naming accused | Section 173, cognizance |
| Closure Report | Report filed when investigation finds insufficient evidence to prosecute | Section 173(2) |
Common Mistakes
Misconception: Police have discretion to conduct a "preliminary verification" before registering an FIR whenever they think a complaint seems weak. Why it's wrong: Lalita Kumari (2014) makes registration of the FIR mandatory the moment information discloses a cognizable offence — no preliminary inquiry is permitted as a general rule. Correct understanding: A preliminary inquiry is allowed only in specific categories (matrimonial/family disputes, commercial disputes, corruption cases, medical negligence, cases with abnormal delay) and must be completed quickly and be entered in a General Diary — it cannot be used as a routine screening tool for ordinary cognizable offences.
Misconception: A statement recorded by police under Section 161 can be read out in court as proof of what happened. Why it's wrong: Section 162 CrPC specifically bars using a Section 161 statement as substantive evidence of the facts it contains. Correct understanding: A Section 161 statement can only be used to contradict the witness if they say something different at trial (Evidence Act, Section 145) — it is a memory aid and accountability tool, not proof.
Misconception: Investigation, inquiry, and trial are just different names for the same process. Why it's wrong: They are distinct statutory stages performed by different actors for different purposes, and confusing them leads to procedural errors. Correct understanding: Investigation is the fact-gathering stage conducted by police (Chapter XII); inquiry is a judicial proceeding, other than a trial, conducted by a Magistrate to decide something short of guilt or innocence (e.g., whether to commit a case to Sessions); trial is the full judicial process that ends in conviction or acquittal.
Comparison and Connections
| Feature | Investigation | Inquiry | Trial |
|---|---|---|---|
| Who conducts it | Police officer | Magistrate / Court | Court (Magistrate or Sessions Judge) |
| Statutory basis | Chapter XII CrPC (S.154-176) | Section 2(g), various Chapters | Chapters XVIII-XXVI CrPC |
| Purpose | Gather evidence, identify accused | Judicial determination short of guilt/innocence | Determine guilt or innocence |
| Outcome | Final report (chargesheet or closure) | Committal order, discharge, or referral | Conviction or acquittal |
| Evidentiary standard | No standard — fact-finding | Court applies judicial mind to material | Proof beyond reasonable doubt |
Practice Questions
Recall
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Under which section of the CrPC must an officer in charge of a police station register information about a cognizable offence? Answer guidance: Section 154 CrPC. Registration is mandatory once the information discloses a cognizable offence, per Lalita Kumari v. Govt. of NCT of Delhi (2014).
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What is a case diary, and under which section is it maintained? Answer guidance: A day-to-day record of the investigation's progress maintained by the investigating officer under Section 172 CrPC. It is not evidence itself and is subject to restricted access by the court and accused.
Understanding
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Explain why a Section 161 statement cannot be used as substantive evidence at trial. Answer guidance: Section 162 CrPC bars its use as proof of the facts stated because it is unsigned, not given under oath, and recorded unilaterally by the investigating officer without judicial safeguards. Its only use is to contradict the witness under Section 145 of the Evidence Act if they change their account at trial.
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Why did the Supreme Court in Lalita Kumari restrict preliminary inquiries to a narrow set of categories? Answer guidance: To prevent police from using "verification" as a pretext to avoid registering FIRs, especially in cases against powerful accused persons, which would undermine victims' access to justice and allow evidence to be lost or tampered with during the delay.
Application
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A woman reports that her husband assaulted her (a cognizable offence). The station officer tells her he will first "verify" the complaint before registering an FIR. Is this lawful? Answer guidance: No — since the offence disclosed is cognizable, Section 154 mandates immediate registration. While matrimonial disputes are one of the Lalita Kumari categories where limited preliminary inquiry is permitted, that inquiry must be brief (typically within 7-15 days), recorded, and cannot be used to indefinitely delay or avoid registration, especially where the allegation is physical assault rather than a purely civil matrimonial dispute.
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Police search a house without a warrant, believing stolen property is hidden there and fearing it will be moved. What must they do to make this search lawful under Section 165? Answer guidance: The officer must record in writing the grounds for the belief and the specific items being searched for before conducting the search, must conduct it personally where practicable, and must comply with the general safeguards under Section 100 — including having two independent witnesses present and preparing a seizure memo (panchnama).
Analysis
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Compare the evidentiary value of a Section 161 statement with a Section 164 confession recorded by a Magistrate. Answer guidance: A Section 161 statement is unsigned, recorded by police without oath, and inadmissible as substantive evidence — usable only to contradict the witness. A Section 164 statement/confession is recorded by a neutral judicial officer after explaining the consequences, carries greater reliability, and (if voluntary and properly recorded) can form the basis of conviction as substantive evidence, subject to corroboration requirements developed by case law.
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A chargesheet is filed under Section 173, but the defence argues the case diary shows inconsistencies that should be shown to them. Evaluate whether the defence has a right to inspect the case diary. Answer guidance: Generally no — Section 172(3) restricts access to the case diary; the accused has no automatic right to call for or use it. It becomes relevant only if the court uses it to aid the trial, or if the investigating officer refers to it to refresh their memory while testifying, in which case the accused may use the specific portion referred to for cross-examination, not the entire diary.
FAQ
1. What is the difference between an FIR and a complaint? An FIR under Section 154 relates specifically to information about a cognizable offence given to police, which triggers police-led investigation without needing a Magistrate's order. A "complaint" under Section 2(d) CrPC is an allegation made to a Magistrate with a view to their taking action, and is the route typically used for non-cognizable offences or where a private party wants a Magistrate to take direct cognizance rather than route the matter through police investigation.
2. Is BNSS 2023 now the applicable law instead of CrPC? Yes. The Bharatiya Nagarik Suraksha Sanhita, 2023 (BNSS) has replaced the CrPC 1973 as the current procedural code in India. Most of the CrPC's investigation framework — FIR registration, police powers, search and seizure, the final report — has a corresponding provision under the BNSS, generally renumbered (for example, FIR registration duties are now addressed in the BNSS's early sections dealing with information to police). Students should learn the underlying CrPC principles thoroughly, since courts and case law built up under the CrPC remain the interpretive foundation, and then map each provision to its BNSS equivalent as their coursework requires.
3. Can a Magistrate order police to register an FIR if they refuse? Yes. Under Section 156(3) CrPC, a Magistrate empowered to take cognizance can direct the police to register an FIR and investigate a cognizable offence if the police have refused to do so. This is a widely used remedy, particularly where the accused is influential or the local police are reluctant to act.
4. What happens if the investigation is not completed within a reasonable time? Prolonged investigation, especially where the accused is in custody, can trigger default bail under Section 167(2) if the chargesheet is not filed within the statutory period (60 or 90 days depending on the offence). Courts also have inherent power to monitor unduly delayed investigations and can direct time-bound completion, particularly in cases involving personal liberty.
5. Does a closure report end the matter permanently? Not necessarily. When police file a closure report (also called a "final report" under Section 173(2) concluding no case is made out), the Magistrate can accept it, or can disagree and either direct further investigation or take cognizance on the existing material despite the police's conclusion. A complainant can also object to a closure report and press for the Magistrate to take cognizance.
Quick Revision
- FIR under Section 154 CrPC must be registered immediately for any cognizable offence — Lalita Kumari (2014) makes this mandatory
- Preliminary inquiry before FIR is allowed only for narrow categories (matrimonial, commercial, corruption, medical negligence, delayed complaints) and must be quick and recorded
- Section 156: police may investigate cognizable offences without a Magistrate's order; Section 155: non-cognizable offences need one
- Section 157: officer must proceed to the spot and begin investigation after registering the FIR, reporting to the Magistrate
- Section 161 statements to police are unsigned, unsworn, and cannot be used as substantive evidence (barred by Section 162) — only for contradiction
- Section 164 statements/confessions are recorded by a Magistrate after explaining rights, and can be substantive evidence if voluntary
- Section 165 allows warrantless search on recorded grounds when a warrant would cause undue delay; Section 100 safeguards (independent witnesses, panchnama) apply
- Case diary under Section 172 records daily investigation progress; accused has no general right to inspect it
- Section 173 final report (chargesheet) concludes investigation — sent for trial if evidence sufficient, or closure report if not
- BNSS 2023 is the current law replacing CrPC 1973 — the investigation framework carries over with renumbered provisions
Related Topics
Prerequisites: Introduction to Criminal Procedure Law, Arrest and Detention
Related Topics: Evidence Collection, Prosecution, Bail and Parole
Next Topics: Trial Procedures, Defense Rights