EWJ June 61 2025 web - Flipbook - Page 104
weapons and how they function. Although all firearms
share the same basic purpose—firing a projectile toward a target—there are numerous designs and
mechanisms that influence how they operate.
The role of Air Weapons and their classification
Air weapons, commonly used for sport and pest control, have strict classification guidelines. Forensic analysis helps determine their legality based on:
• Muzzle energy: Air pistols exceeding 6 foot-pounds
and air rifles over 12 foot-pounds require certification.
Some of the key firearm types encountered in
forensic investigations can include:
1. Handguns
• Semi-automatic pistols: Fire one round per trigger
pull and reload automatically from a magazine.
• Modifications: Some air weapons are unlawfully
altered to increase power, making them classified as
firearms.
• Revolvers: Use a rotating cylinder to hold ammunition; each chamber aligns with the barrel when fired.
• Test firing: Chronograph testing measures velocity
to assess compliance with UK law.
2. Rifles
• Bolt-action rifles: Require manual operation of the
bolt to chamber the next round.
The importance of Ammunition Examination
Ammunition is crucial in forensic investigations, with
experts analysing:
• Calibre and manufacturer to match bullets to
weapons.
• Lever-action rifles: Use a lever mechanism to
chamber rounds.
• Live or inert status to determine whether seized ammunition is viable.
• Semi-automatic rifles: Fire one round per trigger
pull and reload using gas or recoil-operated cycling
mechanisms.
• Prohibited ammunition types, such as armourpiercing or incendiary rounds.
3. Shotguns
• Pump-action shotguns: Require manual operation
of the fore-end to load a new shell.
The Concept of ‘Readily Convertible’ Firearms
Some blank-firing or deactivated weapons can be
modified to fire live ammunition. Forensic experts assess:
• Ease of modification
• Required tools
• Previous alterations
• Semi-automatic shotguns: Use gas or recoiloperated mechanisms to reload automatically.
• Sawn-off shotguns: Modified to have a shorter
barrel for concealability, often making them
prohibited under UK law.
These assessments are increasingly relevant with the
rise of 3D-printed gun components.
Understanding these firearm types helps forensic
experts determine how a weapon was used in a crime,
whether it has been modified, and whether it meets
legal classification as a prohibited firearm.
Case Studies: The Importance of Firearm
Examination
Anonymised case studies from the webinar
highlighted how forensic firearm examination supports fair legal outcomes by challenging assumptions
and ensuring evidence is interpreted accurately.
The Legal Classification of Firearms in the UK
Firearm legislation in the UK is among the strictest in
the world. Firearms examiners provide critical
expertise in determining whether a weapon is legal,
restricted, or prohibited under UK law.
1. Modified Firearm Assessment
In one case, a shotgun had been seized during a
police operation. Initially, it was classified as a standard
shotgun requiring a certificate. However, upon forensic examination, it was found to have been sawn-off,
reducing its barrel length to below 24 inches, making
it a prohibited weapon under UK law. This reclassification had significant implications for the charges
brought against the suspect.
Key legal considerations include:
Lethality: A ‘firearm’ must discharge a projectile with
a muzzle energy above one joule to be legally classified
as a "lethal barrelled weapon."
• Classification: Firearms fall into categories such as
shotguns, air weapons, antique firearms, and
prohibited weapons.
• Modification: Alterations, such as sawing off a
shotgun barrel or converting a blank-firing weapon to
fire live rounds, can change a weapon’s legal status.
2. Cartridge Case Examination and Ballistics
Matching
A shooting incident left several fired cartridge cases at
the scene. Forensic experts conducted microscopic
comparisons of the recovered casings with test-fired
samples from a suspect’s firearm. The analysis identified distinctive firing pin and extractor marks, confirming that the casings had been fired from that
specific weapon. This evidence was pivotal in securing
a conviction.
• Imitation Firearms: Some replicas, including
blank-firing guns and airsoft weapons, can be mistaken for real firearms, making classification crucial in
legal cases.
• Ammunition Restrictions: Certain types of ammunition, such as armour-piercing or incendiary rounds,
are prohibited.
3. Imitation Firearms and Legal Classification
A suspect was arrested in possession of what appeared
to be a real handgun. However, forensic examination
revealed it was an imitation firearm incapable of
Expert forensic classification ensures that courts
receive accurate assessments of firearm status, helping
to guide appropriate legal outcomes.
EXPERT WITNESS JOURNAL
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JUNE 2025
