In the context of criminal procedure, 'Investigation', 'Inquiry', and 'Trial' are distinct stages, each with a specific purpose, conducted by different authorities, and governed by different provisions of the Code of Criminal Procedure, 1973 (CrPC).

1. Investigation (Sections 154-176 CrPC):

   • Purpose: The primary purpose of investigation is to collect evidence, ascertain facts, and determine whether an offence has been committed and, if so, by whom. It is the first stage after information about a cognizable offence is received.
   • Authority: Conducted exclusively by the police or any person (other than a Magistrate) authorized by a Magistrate.
   • Nature: It is an executive function, not a judicial one. The police have wide powers to search, seize, arrest, interrogate, and record statements during investigation.
   • Commencement: Begins with the recording of a First Information Report (FIR) for cognizable offences or a complaint to a Magistrate for non-cognizable offences.
   • Outcome: Culminates in the submission of a police report (charge-sheet under Section 173 CrPC) to the Magistrate, recommending whether to proceed with the case or not, or a final report (closure report).
   • Accused's Role: The accused generally has limited rights during investigation, primarily the right to silence, legal representation, and to be informed of the grounds of arrest.

2. Inquiry (Sections 2(g), 159, 200-204, 340 CrPC):

   • Purpose: An inquiry is a judicial proceeding conducted by a Magistrate or a court, but it is not a trial. Its purpose is to determine the truth or falsity of certain facts, or to ascertain whether there is sufficient ground to proceed with a trial. It is often a preliminary step before a trial.
   • Authority: Conducted by a Magistrate or a court.
   • Nature: It is a judicial function. It can be conducted in various contexts, such as:
     • Magisterial Inquiry (Section 159): When a Magistrate receives a police report or other information about a cognizable offence, they may hold an inquiry to ascertain facts before deciding whether to take cognizance.
     • Inquiry into Complaints (Sections 200-204): When a private complaint is filed, the Magistrate conducts an inquiry to determine if there is a prima facie case to issue process against the accused.
     • Inquiry into Death (Section 176): In cases of suspicious death, a Magistrate may hold an inquiry.
     • Inquiry into Lunacy/Unsoundness of Mind (Section 328): To determine if an accused is capable of understanding the proceedings.
   • Commencement: Can commence on a police report, a private complaint, or suo motu by a Magistrate.
   • Outcome: May lead to the framing of a charge and commencement of a trial, or discharge of the accused, or other orders depending on the nature of the inquiry.
   • Accused's Role: The accused has more rights than during investigation, including the right to be heard, but the full panoply of trial rights (like cross-examination of all witnesses) may not be available at this stage.

3. Trial (Sections 225-265 CrPC):

   • Purpose: The ultimate objective of a trial is to determine the guilt or innocence of the accused based on evidence presented by both the prosecution and the defence, and to pronounce a judgment of conviction or acquittal.
   • Authority: Conducted by a competent criminal court (Magistrate or Sessions Court).
   • Nature: It is a formal judicial proceeding where the rules of evidence (Indian Evidence Act, 1872) and procedure are strictly followed.
   • Commencement: Begins after a charge has been framed against the accused (or when the accused is brought before the court on a charge-sheet and the court decides to proceed).
   • Outcome: Concludes with a judgment of conviction or acquittal, and if convicted, the imposition of a sentence.
   • Accused's Role: The accused has full rights, including the right to plead guilty or not guilty, to cross-examine prosecution witnesses, to present defence witnesses, to make arguments, and to be represented by a lawyer.

Summary of Differences:

| Feature | Investigation | Inquiry | Trial | | :------------- | :------------------------------------------ | :------------------------------------------ | :----------------------------------------- | | Purpose | Collection of evidence, ascertain facts | Ascertain truth of facts, prima facie case | Determine guilt/innocence, pronounce judgment | | Authority | Police or authorized person | Magistrate or Court | Competent Criminal Court | | Nature | Executive function | Judicial function (not a trial) | Formal Judicial proceeding | | Stage | Pre-judicial, preliminary | Pre-trial or specific fact-finding | Final determination of guilt | | Outcome | Charge-sheet/Final Report | Framing of charge/Discharge/Other orders | Conviction/Acquittal | | Accused's Rights | Limited (silence, legal aid) | More than investigation, less than trial | Full rights (cross-exam, defence) | | Evidence | Statements recorded (not evidence in trial) | Evidence taken (may be basis for trial) | Evidence strictly as per Evidence Act |