Background Information

Fingerprints have been used as a means of positively identifying people for many years. One of the many ways to detect fingerprints is by using fingerprint powders. Fingerprint powers are used by dusting a smooth or nonporous surface. If prints appear they are photographed and lifted from the surface with clear adhesive tape. The tape is then placed on a latent lift card to preserve the print. Another way to detect fingerprints are by using an Alternate Light Source (ALS). ALS is a laser or LED that has different filters to emit a particular wavelength or spectrum of light (used on doorknobs, windows, railings, etc.). A third way of detecting fingerprints is by using the method of Cyanoacrylate. Cyanoacrylate is the process of processing or fuming a surface before applying powders or dye stains (dying surfaces). Typically, Cyanoacrylate is performed on non-porous surfaces and involved exposing the object to cyanoacrylate vapors. The vapors (fumes) will adhere to any prints present on the object allowing them to be viewed with oblique ambient light or a white light source. A final way of detecting fingerprints, is by using the ink and card .print method. This method is carried out by first cleaning the finger. Then the person rolls his or her finger in ink to cover the full area. Then each finger is rolled onto prepared cards from one side of the fingernail to the other. These prints are called rolled prints. Due to all of these different methods, fingerprints are quite easy to collect.