BalliScan 3D
Definition
Foster and Freeman's three-dimensional topographic bullet comparison instrument that maps striated surfaces using structured-light interferometry for both optical and digital comparison workflows.
- Manufacturer
- Foster and Freeman
- Measurement principle
- Structured-light interferometry
- Output
- 3D topographic map of striated bullet surfaces
- Use case
- Optical and digital bullet comparison
Common questions
How does a 3D topographic scan add to what a traditional comparison microscope shows?+
A comparison microscope relies on the examiner visually aligning two bullets side by side under reflected light, while a 3D topographic scan captures the actual surface depth profile of the striations, which allows quantitative correlation algorithms to be applied and lets the digital data be stored, re-examined, or shared without needing the physical evidence present again.
Does using an instrument like this replace the examiner's comparison judgment?+
No, the instrument produces measurement data and can support statistical correlation scoring, but the identification conclusion in most jurisdictions still rests on trained examiner interpretation of the striae pattern, with the digital topographic data serving as documentation and an analytical aid rather than an automated verdict.
Why is surface topography particularly suited to bullet striation comparison?+
Striations are physical grooves cut into the bullet surface by imperfections in the barrel, so their identifying information is fundamentally a depth and contour pattern rather than a purely visual one, which makes a technique that directly measures surface height, rather than only reflected light appearance, well matched to the evidence.
Related terms
- AFTE Theory of Identification
- The Association of Firearm and Tool Mark Examiners' standard (1992, revised 2011) for reporting tool-mark comparison conclusions as Identification, Inconclusive, or Elimination...
- Class Characteristics
- Features deliberately or systematically imparted to a group of items by design or manufacture, such as the calibre of a bullet, the...
- Comparison Microscope
- Two compound microscope bodies connected by an optical bridge that presents one half of each body's image in a single split eyepiece...
- Consecutive Matching Striae (CMS)
- A run of adjacent, individually corresponding striae observed across two bullets in the comparison microscope split field. The length of the longest...
- Individual Characteristics
- Surface features on a fired bullet or cartridge case that arise from random or unique events (tool wear, corrosion, service damage) and...
- Leica FSC
- Leica Forensic Comparison System; a motorised zoom comparison microscope used in firearms and toolmark examination at CFSL laboratories in India, European national...
- PCAST Report (2016)
- The President's Council of Advisors on Science and Technology 2016 report on forensic science that found firearms mark analysis had not yet...
- Projectina PAG II
- A high-precision Swiss comparison microscope with motorised stages and quantitative striation-angle measurement, used at Swiss cantonal forensic labs and German LKA laboratories.
- Striations
- Fine parallel scratches on a fired bullet's surface, produced by asperities on the barrel's land surfaces. Each striation reflects the surface topography...