Loop
Definition
A fingerprint pattern in which ridges enter from one side, recurve, and exit on the same side. The most common pattern type (approximately 60-65% of fingerprints). Subcategorised as ulnar (recurving toward the little finger) or radial (recurving toward the thumb).
- Frequency
- Approximately 60-65% of fingerprints
- Deltas
- One
- Subtypes
- Ulnar, radial
- Ridge count
- Counted from delta to core
Common questions
What distinguishes a loop from a whorl?+
A loop has exactly one delta and its ridges recurve back out the same side they entered. A whorl has two deltas and at least one ridge that completes a full circuit around the core.
How is an ulnar loop told apart from a radial loop?+
Ulnar loops recurve toward the little-finger side of the hand and radial loops recurve toward the thumb side. The classification depends on which hand the print came from, not on the pattern's orientation on the page.
Related terms
- ACE-V
- Analysis, Comparison, Evaluation, Verification: the four-stage method for latent print examination used by accredited forensic fingerprint laboratories. Analysis examines the latent in...
- Arch
- A fingerprint pattern in which ridges flow across from one side to the other without recurving and without enclosing a central area....
- Core
- The approximate centre of a fingerprint pattern. In a loop, it is identified as the innermost recurving ridge's peak or the tip...
- Delta (Triradius)
- The point of convergence of three ridge systems in a loop or whorl, visible as a Y-junction or triangular confluence. Loops have...
- Henry Classification System
- The fingerprint filing and retrieval system developed by Edward Henry with Haque and Bose in Bengal in the 1890s and adopted by...
- 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...
- Ridge Counting
- For loop patterns: the number of ridges crossing an imaginary straight line drawn from core to delta, excluding the core and delta...
- Ridge Tracing
- For whorl patterns: following the ridge issuing from the inner side of the left delta toward the right delta and recording whether...
- Whorl
- A fingerprint pattern in which at least one ridge makes a complete circuit around a central area, or forms a related closed...