Criminal Investigation: From Complaint to Charge Sheet

A criminal case can begin in one of two ways, and the distinction shapes everything that follows. The first route is a report of a cognizable offence made to the police, which the officer in charge of a police station is legally required to record as an FIR.

Cognizable offences are the more serious category of crime, typically carrying a sentence of three years or more, where the police can register a case, investigate and arrest without needing prior permission from a magistrate. A theft, an assault causing serious injury, or a robbery falls into this category.

The second route is a private complaint made directly to a magistrate under the criminal procedure code, used most often for non-cognizable offences, where the police need judicial authorisation before they can investigate, or where a complainant chooses to bypass the police altogether. A magistrate receiving such a complaint can order an inquiry, direct the police to investigate, or, in narrow circumstances, take direct cognizance of the offence and proceed to trial without a police investigation at all.

The two routes are not interchangeable by choice. If information discloses a cognizable offence, the Supreme Court held in Lalita Kumari v. Government of Uttar Pradesh (2014) that registering an FIR is mandatory and the police have no discretion to conduct a preliminary inquiry first, except in a narrow list of situations such as matrimonial and family disputes, commercial disputes, medical negligence, corruption cases, or where there has been an unexplained long delay in reporting. Outside that list, refusal to register is itself unlawful.

This first fork matters because everything downstream, from evidence collection powers to time limits on custody, depends on which track a case sits on. A wrongly refused FIR does not just delay a case, it can let evidence go cold before any formal investigation begins.

An FIR is meant to be a first, contemporaneous account, not a polished legal document. It records the date and time information was received, the substance of what was reported, the identity of the informant where known, and the offence disclosed.

Under India's Bharatiya Nagarik Suraksha Sanhita (BNSS) 2023, which replaced the Code of Criminal Procedure, 1973 with effect from 1 July 2024, this provision now sits at Section 173, and information may be given orally, in writing, or through electronic communication, with the officer required to reduce it to writing and read it back to the informant before obtaining a signature.

A recurring practical problem is jurisdiction: a victim may report a crime at a police station far from where the offence occurred, sometimes because that is the nearest station, sometimes because a victim of a serious crime is found or brought elsewhere before reporting is possible. The zero FIR mechanism closes this gap.

Any police station can register an FIR for a cognizable offence regardless of where it occurred, entering it with a serial number of zero, and must then transfer it to the station with actual territorial jurisdiction to continue the investigation.

Section 173(1) of the BNSS now gives this practice explicit statutory footing through the words permitting registration irrespective of the area where the offence was committed, formalising a safeguard that had developed through police guidelines following the widely reported 2012 Delhi gang rape case.

What happens if an officer still refuses to register an FIR? A complainant can approach a superior police officer, and if that fails, can move a magistrate under the code, who can direct the police to investigate. This layered remedy is the direct consequence of the mandatory-registration rule in Lalita Kumari: if registration were purely discretionary, the officer's refusal would be almost unreviewable, but because it is a duty, its breach can be challenged.

None of this means every FIR is later proved true. Registration is a threshold act, not a finding of guilt, and a case can still close with no charge sheet if the investigation finds no evidence to support the complaint.

Arrest is the point at which a criminal investigation most directly restricts a person's liberty, so the power is bounded on both sides: what a warrant is for, and when the police may arrest without one.

A warrant is a written order from a magistrate authorising an arrest; it is generally used for less urgent situations or where a person has failed to appear despite a summons. Most arrests in ordinary criminal investigation happen without a warrant, because the offence is cognizable and urgent action is judged necessary to prevent flight, tampering with evidence, or further harm.

Under the BNSS, Section 35 sets out the conditions for arrest without a warrant, largely carrying forward the earlier Section 41 of the CrPC. An officer must have reasonable grounds to believe a cognizable offence has been committed by the person, or that arrest is necessary to prevent the offence continuing, to properly investigate, or to prevent the person tampering with evidence or influencing witnesses.

A distinct protection was added for offences carrying a maximum sentence under three years where the accused is 60 years or older or infirm: Section 35(7) requires the officer to obtain prior permission from an officer not below the rank of Deputy Superintendent of Police before making that arrest.

Arrest itself is not automatic even where the legal grounds exist. Courts have repeatedly stressed that arrest should be the exception rather than the routine first step of investigation, particularly for less serious offences, because release on bail or a notice of appearance can achieve the same investigative purpose without custody. This distinction between having the power to arrest and it being necessary to exercise it is one of the most litigated points in Indian criminal procedure.

In the United States, the equivalent constitutional floor comes from the Fourth Amendment's requirement of probable cause, and in England and Wales from the Police and Criminal Evidence Act 1984 (PACE), which requires an arresting officer to have reasonable grounds for suspecting the person of an offence and reasonable grounds for believing arrest is necessary, rather than merely convenient, for one of a defined list of policing purposes.

Because arrest happens fast and often without prior notice, the safeguards attached to it are procedural rather than substantive: they do not ask whether the arrest was justified, only whether it was conducted transparently. The starting point is a constitutional guarantee.

Article 22(1) of the Constitution of India requires that a person arrested be informed, as soon as may be, of the grounds for the arrest, and gives the right to consult and be defended by a legal practitioner of choice.

The Supreme Court gave these guarantees operational force in D.K. Basu v. State of West Bengal (1997), issuing eleven binding directions to curb custodial abuse and disappearance.

The arresting officer must prepare a memo of arrest at the time of arrest, recording the date and time, attested by at least one witness, who should be a family member of the arrestee or a respectable person from the locality, and countersigned by the arrestee, with a copy given to the arrested person.

The arrested person is entitled to have a friend, relative, or other known person informed of the arrest and the place of detention as soon as practicable. Police personnel making the arrest must wear clear, visible identification.

These are not courtesies, they exist because the period immediately after arrest, before any judicial officer is aware a person has been taken into custody, is where enforced disappearances and custodial violence have historically occurred. A signed, witnessed memo naming the time and place of arrest makes that period traceable rather than invisible.

Comparable protections exist elsewhere in different form. In England and Wales, PACE Code C requires that a detained person be told the reason for arrest and their rights, including free legal advice, and a custody record is opened immediately on arrival at the station.

In the United States, the Miranda warning, following the Supreme Court's 1966 ruling in Miranda v. Arizona, requires that a person in custodial interrogation be told of the right to remain silent and the right to an attorney before questioning begins, though the warning attaches to interrogation rather than to the physical act of arrest itself.

Police custody exists to let investigators question a suspect and pursue leads while the trail is fresh, but because it places a person under direct police control rather than in a neutral facility, the law caps how long it can last and requires judicial oversight from very early on.

Under the BNSS, Section 58 requires that an arrested person be produced before a magistrate within 24 hours of arrest, excluding travel time, carrying forward a limit that has existed in Indian criminal procedure since well before independence.

Beyond that first 24 hours, further detention needs a magistrate's authorisation. Section 187 of the BNSS allows a magistrate to authorise custody, police or judicial, for up to 15 days at a stretch, and caps total police custody within the initial investigation period at 15 days out of a 60 or 90 day window depending on the severity of the offence, before the accused becomes entitled to bail if the charge sheet has not been filed.

This is often called default or statutory bail, and it exists precisely to stop an investigation stretching indefinitely while a person sits in custody without formal charges being tested in court.

The time limit is not a formality. Custodial interrogation, by its nature, happens away from public view, and the shorter the permitted window, the smaller the opportunity for the kind of abuse the D.K. Basu guidelines were designed to prevent. Independent oversight, mandatory medical examination on production before a magistrate, and the requirement that any extension be judicially authorised rather than granted by the police themselves, are the structural checks against that risk.

Other systems use a shorter clock with a similar logic. Under PACE in England and Wales, a suspect can normally be held for up to 24 hours before being charged or released, extendable to 36 hours by a superintendent for a serious offence and to a maximum of 96 hours with authorisation from a magistrates' court.

In the United States, the Supreme Court held in County of Riverside v. McLaughlin (1991) that a person arrested without a warrant must generally receive a judicial determination of probable cause within 48 hours, after which the burden shifts to the state to justify any delay.

Alongside arrest, investigators gather physical evidence through search and seizure, governed by warrant requirements for most searches of premises and narrower powers to search a person or a place without a warrant in urgent circumstances.

This topic covers that power only briefly, because what makes seized evidence usable at trial is a separate question of admissibility, governed in India by the Bharatiya Sakshya Adhiniyam, 2023, which replaced the Indian Evidence Act, 1872, and covered in this corpus under cyber-forensics and the wider law of evidence.

Every investigation, whether or not it produces enough evidence to proceed, ends with a report filed by the investigating officer. Where the evidence supports a trial, this is popularly called a charge sheet, and under the BNSS it is filed under Section 193, which now also requires the investigating officer to maintain a documented chain of custody for any electronic evidence seized and to update the informant or victim on the progress of the investigation within ninety days of the FIR being recorded.

Where the evidence does not support proceeding, the officer instead files a report recommending closure, which a magistrate can accept, reject and order further investigation, or use as a basis to still take cognizance and proceed against the accused.

The charge sheet is not itself a verdict. Filing it moves the case from a police-controlled investigation into the judicial process: a magistrate examines it to decide whether there is sufficient ground to proceed, and if so, the case moves toward framing of charges and trial.

Everything upstream in this topic, from the FIR to the arrest memo to the custody clock, exists to make that transition defensible, since a trial built on an unrecorded complaint, an unlawful arrest, or evidence gathered outside legal limits is far more vulnerable to challenge, and can result in evidence being excluded or the case collapsing altogether.

Set against other systems, the clearest structural difference is who decides whether a case goes to trial. In India, the investigating officer files the charge sheet and a magistrate examines it to decide whether to proceed, with no separate prosecutorial charging decision beforehand.

In the United States, prosecutors typically make that decision themselves, by filing an information or, for serious federal offences and in many states for felonies, by presenting evidence to a grand jury that decides whether to issue an indictment. In England and Wales, the Crown Prosecution Service reviews the police file under a two stage test of evidential sufficiency and public interest before authorising a charge, separating the investigating and charging roles more sharply than the Indian model does.

The safeguards travel across systems even where the institutions that apply them do not: a recorded first report, a time-limited custody clock, and an independent check before a case reaches trial are the same three ideas wearing different statutory names.