Question

What are the three chemical techniques that fingerprint specialists traditionally rely on for developing latent fingerprints? List them in the order of how they should be used.

Answer 1

The three chemical techniques that fingerprint specialists traditionally rely on for developing latent fingerprints are dusting, ninhydrin, and cyanoacrylate fuming.

Step-by-step explanation:

The three chemical techniques that fingerprint specialists traditionally rely on for developing latent fingerprints are:

1. Dusting: Fingerprint dusting involves using a fine powder, such as black or white powder, to make the latent fingerprints visible. The powder adheres to the oily residue left behind by the ridges of the fingerprint, making it easier to see and photograph.
2. Ninhydrin: Ninhydrin is a chemical reagent that reacts with amino acids in the sweat of fingerprints. When ninhydrin is applied to a porous surface, such as paper or cardboard, it reacts with the amino acids to produce a purple or brown coloration, making the latent fingerprints visible.
3. Cyanoacrylate fuming: Cyanoacrylate fuming involves exposing the latent fingerprints to vapors of cyanoacrylate, which is commonly known as super glue. When cyanoacrylate reacts with moisture present in the latent fingerprints, it forms a white, solid material that adheres to the ridges of the fingerprint, making it visible.

The order in which these techniques should be used depends on the nature of the surface and the condition of the latent fingerprints.

Generally, dusting is used first to see if any visible prints can be detected. If dusting is not effective, ninhydrin can be used on porous surfaces, followed by cyanoacrylate fuming for non-porous surfaces.