|
Fingerprint powders are fine powders used in dusting for fingerprints by crime scene investigators and others in law enforcement. The process of dusting for fingerprints involves various methods intended to get the particles of the powder to adhere to residue left by friction ridge skin on the fingers, palms, or feet. Physical development of fingerprints using powders is just one of a selection of methods used to develop fingerprints. Fingerprints often leave residues of oils in the shape of the friction ridges, but the friction ridge skin itself does not secrete oils, and so some fingerprints will only leave a residue of amino acids and other compounds which the powder does not adhere to well. For this reason, 'dusting' is used as part of an array of techniques to develop fingerprints, but is often used on larger areas in a crime scene which cannot be removed for analysis, or cannot be subject to more rigorous analysis for other reasons. Fingerprint powders have various formulations, and the appropriate powder must be used on the appropriate surface. For example, dark coloured powders will show up a fingerprint far better on a light surface. ==Application== Powders may be applied with a fingerprint brush, a brush with extremely fine fibers designed to hold powder, and deposit it gently on the fingerprint to be revealed, without rubbing away the often delicate residue of the fingerprint itself. They may also be applied by blowing the powder across the fingerprint, or by pouring the powder onto the print, and then blowing away the excess. Magnetic powders are also used, where a fine magnetic powder is held by a magnetic applicator, which may then be gently moved across the fingerprint. As no bristles touch the surface, this often damages the print less than other methods of developing the print. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「fingerprint powder」の詳細全文を読む スポンサード リンク
|