What is the offence under s.139 CJA 1988?

Having a bladed article in a public place with no good reason. The related offences are s.139A CJA 1988 (knife on school premises), and s.1 / s.1A Prevention of Crime Act 1953 (offensive weapon in a public place, and threatening with an offensive weapon in a public place).

What should an officer do first at a knife-crime scene?

Cordon the scene immediately, preserve the weapon in situ — do not move it — and request forensics attendance before photographing the weapon and bagging exhibits separately.

Knife Crime & Offensive Weapons

The offensive-weapon and bladed-article offences, the stop-and-search powers used against them, scene management, victim first aid, and county lines exploitation indicators — an officer quick-reference.

Unofficial independent resource — always verify with official sources (College of Policing, your force, PFEW).

Reviewed by the BlueLineHub Editorial Team

Last reviewed: 25 August 2026 · Next review due: 25 February 2027

Reviewed by BlueLineHub Editorial

What are the main knife crime and offensive weapon offences and how are stop-and-search powers used against them?

The key offences are s.1 Prevention of Crime Act 1953 (offensive weapon in a public place, made, adapted, or intended), s.139 Criminal Justice Act 1988 (bladed article in a public place, no good reason), s.139A CJA 1988 (knife on school premises), and s.1A Prevention of Crime Act 1953 (threatening with an offensive weapon in a public place). Offensive weapons fall into three categories: made for causing injury (e.g. knuckle duster, flick knife, butterfly knife), adapted for injury (e.g. broken bottle, sharpened screwdriver), and intended for injury (any object carried with intent to harm).

The stop-and-search powers most often used are s.1 PACE (reasonable grounds to suspect a prohibited article or stolen goods) and s.60 CJPOA 1994 (an anticipatory power authorised by an Inspector or above where serious violence is likely, requiring no individual grounds) — GOWISELY applies to both.

All operational references

A reference to the key knife-crime and offensive-weapon offences, the stop-and-search powers most often used against them, scene management, first aid for a stabbing victim, and the signs of county lines exploitation. It is educational reference, not tactical guidance — follow your force policy, training and current law.

Stop & Search Powers

s.1 PACE — Reasonable Grounds

Reasonable grounds to suspect a person has a prohibited article or stolen goods. You must have individual, objective grounds for suspicion. GOWISELY applies.

s.60 CJPOA 1994 — Anticipatory Power

Authorised by an Inspector or above if serious violence is likely in an area. No individual grounds needed — allows search of anyone in the defined area and time period. GOWISELY still applies.

Key Offences

Section	Description
s.1 Prevention of Crime Act 1953	Offensive weapon in a public place (made, adapted, or intended).
s.139 Criminal Justice Act 1988	Bladed article in a public place (no good reason).
s.139A CJA 1988	Knife on school premises.
s.1A Prevention of Crime Act 1953	Threatening with an offensive weapon in a public place.

Offensive Weapons — Definition

Three categories of offensive weapon in law.

Category	Examples
Made for causing injury	Knuckle duster, flick knife, butterfly knife
Adapted for injury	Broken bottle, sharpened screwdriver
Intended for injury	Any object carried with intent to harm

Scene Management

Cordon the scene immediately
Preserve weapon in situ — do not move
Request forensics attendance
Photograph weapon before moving
Bag separately from other exhibits
Check for blood and DNA evidence

Victim First Aid

Immediate actions — keeping the casualty alive until paramedics arrive.

Apply direct pressure to the wound
Elevate the injury if possible
Call ambulance immediately
DO NOT remove an embedded weapon — stabilise it in place
Monitor for signs of shock
Keep the casualty warm

County Lines Awareness — Signs of Exploitation

Young and vulnerable people exploited to transport drugs across county borders.

Unexplained money or possessions
Absent from school or home
Travelling alone to unfamiliar areas
New phone or SIM card
Unexplained injuries

NRM Referral: If you suspect exploitation, refer to the National Referral Mechanism.

Cuckooing: Drug dealers taking over a vulnerable person's home to use as a base.

Frequently asked

What is the offence under s.139 CJA 1988?: Having a bladed article in a public place with no good reason. The related offences are s.139A CJA 1988 (knife on school premises), and s.1 / s.1A Prevention of Crime Act 1953 (offensive weapon in a public place, and threatening with an offensive weapon in a public place).
What stop-and-search powers apply to a knife-crime encounter?: s.1 PACE (reasonable grounds to suspect a prohibited article or stolen goods) and s.60 CJPOA 1994 (an anticipatory power authorised by an Inspector or above where serious violence is likely, requiring no individual grounds). GOWISELY applies to both.
What should an officer do first at a knife-crime scene?: Cordon the scene immediately, preserve the weapon in situ — do not move it — and request forensics attendance before photographing the weapon and bagging exhibits separately.