Firearms Evidence and the Crime Scene Investigation

A common form of evidence found at many crime scenes is firearms evidence.  It can be in the form of a gun, shell casings, bullets, or any combination.  This type of evidence can be found in related crimes such as murder, attempted murder, suicide, robbery, assault, and rape. 

It’s a fascinating and challenging technique for forensic scientists to begin to discover all of the characteristics of a particular firearm and how it was applied to the crime.

Firearms evidence can answer so many questions about a crime scene and can provide investigators with the answers to solve the crime and arrest the perpetrator. 

What type of weapon was used in the crime? 

How far away was the perpetrator when they fired the weapon? 

Was the weapon in proper working order? 

Who was the perpetrator? 

Why did they use the gun? 

The importance of reconstructing the crime scene can’t be overstated when it comes to firearms evidence.  Firearms identification refers to ballistics and the study of firearms, which includes the operation of the firearms, cartridges, bullet comparisons, powder patterns, and gunshot residue.  These identifications are extremely important to forensic scientists and criminal investigators.  They provide a detailed roadmap of clues of what exactly happened and provide a timeline of events.   

The characteristics of firearms are divided into two broad groups: shoulder firearms and handguns, which can be further characterized by smoothbore and rifled weapons. 

Basically, the rifling in a gun barrel is the spiral grooves cut into the barrel that reflects the twisting motion on the bullet as it leaves the barrel.  This is what firearms examiners use to compare bullets from a crime scene and can be extremely important in any criminal investigation and prosecution. 

Another important forensic tool in firearms evidence are the scratches or striations that are caused by the imperfections in the grooves placed in the barrel at the time of manufacture.  The use of the weapon also causes distinct scratches and striations.  This reflects the individual marking(s) of a particular gun and bullet and can identify the perpetrator. 

Firearms evidence is similar to the types of characteristics of fingerprints.  They are distinct and an extremely useful form of forensic evidence. 

Guns account for many of the violent crimes today, but the crime scene and firearms evidence can reveal the clues to solve the mystery and bring the guilty to justice.  

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About jchasenovelist

Published thriller author, criminologist, and blogger.
This entry was posted in crime, Forensic and tagged , , , , , , . Bookmark the permalink.

2 Responses to Firearms Evidence and the Crime Scene Investigation

  1. zencherry says:

    Coolness! I didn’t know gun barrels were like fingerprints. Nice little bit of knowledge there for a book’s believability-factor! Thanks! 😀


  2. TriniCSI says:

    One aspect of forensics that has always been difficult to find is the fingerprints placed on the ammunition cases before they were fired.
    The combustion burns away the fingerprints and DNA evidence that has been recoverable if the weapon is not fired.
    To that end various companies are trying to find ways of gaining this important evidence back again and one company is Consolite Forensics Ltd.
    They developed the C.E.R.A. device which is now available from various companies around the world and it is a worlds first.
    These fingerprints are available to be recovered meaning investigators can place the ammunition in peoples hands prior to the execution of the crime/firing of the weapon.
    If you want a demonstration look it up on You Tube or check my other company website (I have some distribution rights) at

    Good post.


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