Typically firearms evidence is used in the investigation of violent crimes against persons such as homicide, robbery, aggravated assault, but could be used in sexual assaults, property, and drug-related crimes. Traditionally examinations comprise the comparison of bullets, and cases of cartridges as they differ per firearm.
Recently examiners have focused on distance based on the residue on gunpowder, or what they call shot. Examination also includes analysis of the functionality or possible modification of the firearm (especially when illegal), gunshot residue analysis, sequence of shots tracing of the owner to name a few of the new features involved in firearm (“Firearms Evidence Collection Procedures, n.d.”). Examiners typically have to provide answers to questions as to whether the discharge was intentional or unintentional; such as a safety failure within the firearm or it was used to inflict injury (Steele, n.d.”).
How is X-ray photography used by forensic firearms examiners?
The use of X-ray photography in the form of radiographs is integral to firearms investigations. This technique is used by criminal investigators as a means of identifying the remains of the deceased. X-ray allows the examiner to see things inside the firearm that is not allowed to be seen with the naked eye. It is a credible technique used in criminal convictions.
“The world is full of obvious things which nobody by any chance ever observes.” Sherlock Holmes-The Hound of the Baskervilles injury (Steele, n.d.”).
This method is used to determine whether the weapon was fully loaded or modified. If there is rust inside the firearm then the X-ray can determine the firing capabilities of the ammunition before it is disassembled for examination. This technique is valuable, as the photography helps to differentiate between two weapons, as they have different inner mechanical structures. Similarly in ballistics X-ray photography provides information about the bullet home like firing distance and type of bullet used. When a weapon is discharged gun powder emits, so X-ray is able to separate the skin or even the clothing from the powder particles from the firearm. X-rays are affordable, and accessible in labs regardless of the size of the firearm(Goode, 2004).
- Ballistics. Retrieved from
- Firearms & Ballistics. Retrieved from http://aboutforensics.co.uk/firearms-ballistics/
- Firearms Evidence Collection Procedures. Retrieved from http://www.crime-scene-investigator.net/CAfirearms.pdf
- Goode, B. (2004). Radiography Uncovers More than Meets the Eye. Retrieved from