What distinguishes an arch fingerprint pattern?

An arch fingerprint pattern is characterized by the absence of a delta, which is a triangular ridge pattern typically found in loop and whorl fingerprint types. Instead of the loops or whorls seen in other fingerprint patterns, arches consist of ridges that enter from one side of the finger, rise in the center, and exit on the opposite side without forming any core or delta structure.

In the case of a plain arch, the ridges create a smooth, continuous rise, while a tented arch may have a more pronounced peak but still lacks a delta. Understanding this characteristic helps in the classification and identification of fingerprints, which is essential in forensic analysis.