Fingerprint powder

[1][2] This method of fingerprint development commonly referred to as dusting for fingerprints, involves the adherence of the powder particles to the moisture and sweat secretions deposited on to surfaces by the raised ridges on fingers, palms, or soles of feet designed for grip, called friction ridges.

It is typically used to search for fingerprints on large non-porous surfaces that cannot be submitted for chemical development within a laboratory.

[3] This particular method is best suited for the enhancement of freshly deposited fingerprints, because the adherence of the powder is diminished when the impression residue has dried.

[3][5] These dry powders can be added to a dilute detergent solution that can be applied to surfaces to develop fingerprints.

[3][5] The materials used to make these powders were chalk, lamp black, graphite and a variety of lead and mercury components.

[3][5] Black granular powders, commonly used in the United States of America, are now composed of carbon-based particles.

[3][6] Particles with shapes that provides a larger surface area promote greater adhesion to the fingerprints.

[3][6][8] The details of fingerprints deposited on light surfaces are best visualized by applying dark or black coloured powders.

[3][6][8] Conversely, white or grey powders are recommended for enhancing fingerprints found on dark surfaces.

[2][3][5][8] Carbon dots based powders adopt different colours depending on the wavelength of the incident radiation, minimising background interference for fingerprints found on multicolour surfaces.

[3] In the past, powders were selected based on personal choice or outlined standard procedures of the associated department or agency.

Kaplan-Sandquist, LeBeau, and Miller conducted a study where they tested fingerprint development methods with the MALDI/TOF MS.

[3][5][6] Modern fingerprint powders pose significantly fewer health risks because they are composed mainly of organic components.

However, there is concern that the small particles within the fingerprint powders may be inhaled and after prolonged exposure can result in the development of lung diseases.

[3] It is recommended that individuals frequently using these powders take the necessary precautions to mitigate the risk of respiratory illness, whether that be working within a fume hood or wearing a mask.