These three techniques share a common logic: each relies on patterns that are unique to the individual and stable through life.
Dactylography (Fingerprints)
Definition: the science of identification based on fingerprints.
Fundamental principles
- Individuality — no two fingerprints are identical.
- Permanency — fingerprints remain unchanged throughout life.
- Classifiability — fingerprints can be systematically classified.
Basic fingerprint patterns
| Pattern | Feature |
|---|---|
| Loop | Ridges enter and leave from the same side |
| Whorl | Circular or spiral ridges |
| Arch | Ridges pass from one side to the other |