Which of the following does NOT influence the chemical composition of a fingerprint?

The correct answer is that body temperature does not influence the chemical composition of a fingerprint. When a fingerprint is deposited, the composition primarily consists of sweat, oils, and various contaminants from the skin. These materials are left behind on a surface when a person touches it.

The nature of the surface can affect how well fingerprints are deposited and recovered but does not change the chemical makeup of the fingerprint itself. For instance, porous surfaces like paper will absorb different elements than non-porous surfaces like glass. Similarly, time since deposition can influence how the fingerprint dries or deteriorates, which may alter the visibility or recoverability of the print, but not its intrinsic chemical composition. Environmental conditions, including humidity and temperature, can also impact the preservation and clarity of a fingerprint after it has been deposited, but they do not affect the actual chemical makeup of the material left behind. Therefore, body temperature, while it may play a role in perspiration levels, does not alter the chemical composition of a fingerprint once it has been deposited.