Idaho Peace Officer Standards and Training (POST) Practice Exam 2025 - Free POST Practice Questions and Study Guide

The most common fingerprint pattern is loops. Loops are characterized by their distinctive ridge patterns that enter from one side of the print, curve around, and exit on the same side. This type of pattern accounts for approximately 60-70% of all fingerprints found in the general population, making it the predominant pattern.

In contrast, whorls make up about 25-35% of fingerprints and have a more complex pattern with circular ridges. Arches are the least common type, representing approximately 5% of fingerprints; they consist of ridges that enter from one side and exit out the opposite side without looping back. Composite patterns, which involve a combination of various types of patterns, are less frequently encountered and do not represent a distinct category when considering the overall frequency of individual patterns. Therefore, loops stand out as the most prevalent fingerprint pattern in forensic analysis and identification.