Types of Fingerprints

Latent- Marks left behind at the scene of a crime which may not be immediatly visible to the naked eye. To expose latent fingerprints, technicians use fingerprint powder, fuming, and other techniques.








Plastic- A friction ridge impression from a finger or palm (or toe/foot) deposited in a material that retains the shape of the ridge detail. Commonly encountered examples are melted candle wax, putty removed from the perimeter of window panes and thick grease deposits on car parts. Such prints are already visible and need no enhancement, but investigators must not overlook the potential that invisible latent prints deposited by accomplices may also be on such surfaces. After photographically recording such prints, attempts should be made to develop other non-plastic impressions deposited at natural finger/palm secretions (eccrine gland secretions) or contaminates.





Direct- These are friction ridge impressions of unknown origins which are obvious to the human eye and are caused by a transfer of foreign material on the finger, onto a surface. Because they are already visible they need no enhancement, and are generally photographed instead of being lifted in the same manner as latent prints. Finger deposits can include materials such as ink, dirt, or blood onto a surface.

History Of Fingerprints

Fingerprints have served the government for the past 100 years. The first forensic professional organization, the International Association for Identification, was established in 1915 and it was invented just to study fingerprints! Around 1870, French anthropologist Alphonse Bertillon invented a system to measure and record the dimensions of certain bony parts of the body. These measurements were reduced to a formula which would apply only to one person and would not change during his or her adult life.

Beginning in the 1850s, some areas began photographing (or daguerrotyping) criminals as they went into prison. This method became more popular in the 1880s, with the advent of the Kodak camera, which was quicker and easier to use. However, photographs were still not foolprrof--people can drastically change their appearance, and what they do not do, time may. Nonetheless, police spent a great deal of time studying "Rogues Galleries"--thick books of photographs of known criminals in the hopes of being able to identify them in the case of similar crimes occuring near them. (There was apparently very little faith that a criminal wouldn't return to his or her illicit ways).