Final answer:
Scientists have categorized fingerprints into types such as whorls, arches, and loops, which form during fetal development and are unique to each individual.
Step-by-step explanation:
The types of fingerprints that scientists have identified are known as whorls, arches, and loops. These are the patterns that are formed where the cells of the stratum basale meet the papillary layer of the dermis during fetal development. These patterns remain the same throughout a person's life, making them ideal for forensic analyses.