Projectina PAG II
Definition
A high-precision Swiss comparison microscope with motorised stages and quantitative striation-angle measurement, used at Swiss cantonal forensic labs and German LKA laboratories.
- Origin
- Switzerland
- Function
- Comparison microscope
- Feature
- Motorised stages, striation-angle measurement
- Used by
- Swiss cantonal labs, German LKA laboratories
Common questions
What advantage does quantitative striation-angle measurement give over traditional visual bullet comparison?+
Traditional comparison relies on the examiner's visual pattern matching of striations side by side, while quantitative angle measurement produces a numeric value for the striation geometry, supporting a more objective, reproducible record of the basis for a match that can be reviewed independently of the original examiner's judgement.
Is the Projectina PAG II unique to firearms examination?+
No, comparison microscopes of this general design are also used for toolmark and other striated-surface comparisons. The firearms application is one use case among several that rely on the same side-by-side optical comparison principle.
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...
- BalliScan 3D
- 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.
- 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...
- 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...