5.1: Introduction

The first fingerprint development techniques utilized to develop latent fingerprints likely involved holding a non-porous item in the soot produced by the wick of a lit kerosene lamp. Camphor fuming is a very old technique first introduced in India in the late 19th century, which gained popularity again in the early 2000’s for developing fingerprints on un-fired firearm cartridges. A few camphor crystals were placed in a metal spoon and set alight. The item was held above the smoke rising from the spoon until a layer of carbon atoms interacted with excreted sebaceous oils and the aqueous deposits of the fingerprint, producing a dark developed print. Excess carbon could be removed using a camel-hair brush, or with the application of a gentle stream of cold running water. If the developed print was too faint, the process could be repeated. The developed print can be easily lifted using standard tape-lifting methods. The only drawback of the camphor method is that it produces a lot of smoke. It does, however, have a very pleasant odor. At any rate, it is a development medium best completed in an area with a lot of ventilation, and not in a laboratory with a sensitive fire alarm or sprinkler system.

Fingerprint development methods can be divided into two categories: powder development and chemical development. They can also be broken down into practical applications of those methods that can be used in the field (crime scene) and those that can be used in the laboratory; although any method used in the field can also be used in the laboratory. Development mediums can also be grouped by the surface upon which the latent fingerprint is deposited: porous and non-porous. A porous surface is a material that will absorb excretions, like paper or paper products. A non-porous surface is a material that is solid and impervious to excretions, like metal, glass, or plastics.