Preventive Action of the Police (ss.168–172 BNSS) — BNSS (Criminal Law II) Notes

Preventive Action of the Police (ss.168–172 BNSS)

The best crime is the one that never happens. So the Sanhita arms the police not only to detect offences but to prevent them — to step in and physically stop a cognizable offence before it is committed. This is prevention as a police duty, distinct from the Magistrate-led security proceedings of Unit III.

Chapter XI (ss.168–172 BNSS) gives the police preventive powers:

Police to prevent cognizable offences (s.168 [s.149 CrPC]). Every police officer may interpose to prevent, and shall to the best of his ability prevent, the commission of any cognizable offence.
Information of a design to commit (s.169 [s.150 CrPC]). An officer receiving information of a design to commit a cognizable offence must communicate it to his superior and to any officer whose duty it is to prevent it.
Arrest to prevent (s.170 [s.151 CrPC]). An officer knowing of a design to commit a cognizable offence may arrest, without a Magistrate’s order and without warrant, the person so designing, if the offence cannot otherwise be prevented — but such a person shall not be detained beyond 24 hours unless further detention is authorised by law.
Prevention of injury to public property (s.171 [s.152 CrPC]); inspection of the peace by officers (s.172).

🔑 This preventive power is executive and immediate; it is different from the judicial security proceedings before an Executive Magistrate (Unit III, 3.13), which require an inquiry and end in a bond.

🧩 WORKED EXAMPLE — arrest to stop a planned crime

Facts. An officer learns of a definite plan to commit a cognizable offence that night and cannot otherwise stop it.

Rule. Section 170 allows him to arrest the person designing the offence without a warrant, but not to detain beyond 24 hours without lawful authority.

Apply. He may arrest to prevent the crime, then must produce or release the person within 24 hours.

Conclusion. Preventive arrest is lawful but time-limited — it is prevention, not punishment.

Section 168 BNSS: “Every police officer may interpose for the purpose of preventing, and shall, to the best of his ability, prevent, the commission of any cognizable offence.”

In Simple Terms: A police officer has a positive duty to step in and stop a cognizable offence from happening.

flowchart TD
    ROOT["Preventive action of police ss.168-172"]:::root
    ROOT --> A["Duty to prevent cognizable offences s.168"]:::leaf
    ROOT --> B["Report a design to commit s.169"]:::leaf
    ROOT --> C["Arrest to prevent s.170<br/>(no warrant; not beyond 24 hrs)"]:::sidebox
    ROOT --> D["Protect public property s.171"]:::leaf
    classDef root fill:#FFF8DC,stroke:#000,stroke-width:1px,color:#000;
    classDef leaf fill:#E6F3FF,stroke:#1E3A8A,color:#000;
    classDef sidebox fill:#FDE7C9,stroke:#B45309,color:#000;
    linkStyle default stroke:#888,stroke-width:1px;

Case Laws

Ahmed Noormohmed Bhatti v. State of Gujarat (2005) — preventive arrest powers are valid but must be exercised reasonably and not arbitrarily.

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