What completes the definition of a double loop fingerprint?

The defining feature of a double loop fingerprint is the presence of two deltas. In the classification of fingerprints, deltas are significant because they help distinguish between different types of patterns. A double loop pattern consists of two distinct loop formations that intertwine, creating a unique print that is characterized by these two areas where the ridges change direction, forming loops on either side. The two deltas in a double loop pattern are critical because they indicate that the print is not simply a single loop or another fingerprint type but a complex pattern that involves the intermingling of two loop structures.

The presence of two deltas ensures that the fingerprint can be correctly categorized as a double loop rather than being mistaken for other types such as whorls, which typically have a different structure and often involve only one delta or none at all. This specific arrangement is crucial for accurate identification and classification within forensic analysis and is a key component in understanding how various fingerprint patterns are categorized.