|MadSci Network: Chemistry|
The substance most commonly used in the examination of non-porous surfaces such as glass is aluminium powder, applied very lightly with a horsehair brush. The aluminium powder adheres to the acquaeous components of sweat in a latent fingerprint making it visible, this result can then be photographed or 'lifted' using adhesive tape and placing on to an acetate sheet. This process is used daily in British scenes of crime examination, where there is only fingerprint evidence.
Further processes are available under laboratory conditions if items are to be treated for other contaminants.
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