Forensic Chemistry: The Revelation of Latent Fingerprints

The visualization of latent fingerprints often involves the use of a chemical substance that creates a contrast between the fingerprint residues and the surface on which the print was deposited. The chemical-aided visualization techniques can be divided into two main categories: those that chemically react with the fingerprint residue and those that adhere to the fingerprint residue by intermolecular forces. A plethora of empirically effective fingerprint revelation methods have been developed but the chemistry is often incompletely understood. This article briefly describes the chemical rationale of most fingerprint visualization techniques practiced today. This material is suitable for a forensic chemistry course or for an introductory chemistry course to introduce the relevance of chemistry in law enforcement. This material may also apply to an organic or biochemistry course when discussing noncovalent intermolecular interactions.