Impressions left through the contact of friction ridge skin (finger, palm or foot prints) with an object can be useful at crime scenes because it proves contact between an individual and an item or surface.  The orientation of the ridge detail on an item or surface may also be meaningful.  Ridge detail may not be visible (latent) and may need to be enhanced in some way to be identified.  Ridge detail can also be readily visible (patent) as a transfer of some substance such as grease or blood onto another surface or as a three-dimensional impression (plastic) into some substrate such as dust or putty.  The crime scene team has several ways to help identify or enhance ridge detail at scenes.

  i.   Amido Black
 ii.   Fingerprint Powder
iii.   Leucocrystal Violet
iv.   Cyanoacrylate (Superglue) Fuming
 v.   Titanium Dioxide

Images below show a revolver (left) with a visible print on the cylinder (center) that was further enhanced by fuming with cyanoacrylate (right).