What is a potential result of using dirty substrates during fingerprint deposition?

Using dirty substrates during fingerprint deposition can lead to incomplete prints with areas missing. This occurs because contaminants on the substrate can interfere with the quality and transfer of the fingerprint material. When a finger contacts a dirty surface, dirt, oil, or other residues can obscure parts of the print, preventing some characteristics of the pattern from being clearly deposited. As a result, the unique details of the fingerprint, which are critical for identification, may not be fully captured.

Additionally, some of the contaminants might absorb or disperse the oils and moisture naturally present on the skin's surface, leading to areas where the impression is weak or completely absent. The presence of such dirt can hinder the clarity and completeness of the print, making it challenging for forensic analysis later on.