Some parasites are associated with particular environments and specific hosts. Identifying them may therefore provide information about where a person or animal was exposed to infestation. This relationship allows parasites to serve as supporting evidence in investigations involving movement and animal transport. One practical example involved the use of ticks to investigate the movement of a horse across quarantine boundaries. Identifying the tick species and examining its life cycle and minimum age helped assess the owner’s account of where the infestation had occurred. The findings indicated that the horse had been transported while already infested from a region where cattle ticks occurred, contradicting the account provided. This example shows how a parasite may connect its host to a previous environment. Such evidence becomes more useful when reliable information is available about the parasite’s distribution and development, supported by proper documentation of sample collection and preservation. However, parasites do not provide a conclusive geographic fingerprint. They may travel with people or animals, and their distribution can change. Findings should therefore be compared with transport records, environmental information, and other evidence. In conclusion, studying parasites can help test accounts and reconstruct aspects of an event, demonstrating the value of integrating parasitology with forensic science.