Champod Minutia Frequency Study
Definition
Empirical research by Champod and Evett (2001) characterising the frequency distributions of minutia types and spatial configurations from operational fingerprint databases, providing the empirical foundation for likelihood ratio frameworks.
- Authors
- Christophe Champod and Ian Evett
- Year
- 2001
- Data source
- Operational fingerprint databases
- Application
- Likelihood ratio frameworks for minutiae
Common questions
Why was this study significant for fingerprint evidence?+
It moved fingerprint comparison away from a purely subjective, categorical match/no-match judgment toward a probabilistic model grounded in actual measured frequencies of minutia types and their spatial arrangements.
What is a likelihood ratio framework used for here?+
It expresses how much more probable the observed minutiae configuration is under the hypothesis that two prints came from the same finger versus different fingers, giving examiners and courts a quantified strength-of-evidence statement instead of a binary conclusion.
Related terms
- Bifurcation
- A minutia at which a single friction ridge divides into two diverging ridges. One of the two most common minutia types (with...
- Blind Verification
- The procedure in which a second fingerprint examiner independently performs the Analysis and Comparison stages without knowledge of the first examiner's conclusion....
- FRStat
- The fingerprint statistical scoring model developed by the FBI Laboratory and Iowa State University (Professor Alicia Carriquiry). Takes ACE-V comparison documentation as...
- Galton Features
- The set of observable ridge events catalogued by Francis Galton in his 1892 monograph, including ridge endings, bifurcations, and enclosed formations. The...
- Lake (Enclosure)
- A minutia in which a ridge briefly splits into two and immediately re-joins, enclosing an oval space. Less common than endings and...
- Level 1 Detail
- In ACE-V, the broadest level of information extracted from a fingerprint: the overall ridge flow and pattern type (arch, loop, whorl). Level...
- Level 2 Detail
- The intermediate spatial scale: individual minutia (ridge endings, bifurcations, lakes, dots, islands, deltas, cores). Carries the principal discriminative weight in a fingerprint...
- Level 3 Detail
- The finest spatial scale: sweat pore positions, ridge edge contours, incipient ridges. Reliably interpretable only in high-quality inked or latent prints. Used...
- Ridge Ending
- A minutia at which a single friction ridge terminates abruptly. One of the two most common minutia types (with bifurcations). Encoded in...