Forensics: Fingerprinting Analysis

 

The History of Fingerprinting Analysis

These are hand-prints from prehistoric

times, that had been discovered.

 Some of the earliest signs of hand/fingerprinting was found as early on as prehistoric times. A picture writing of a hand with ridge patterns was discovered in Nova Scotia. The next fingerprints were used in ancient Babylon on clay tablets for business transactions.

In ancient China, thumb prints were found on clay seals to also help with the recording of business contracts.

In 14th century Persia, many diverse official government papers had the impressions of fingerprints on the back of them

Marcello Malpighi, a professor of anatomy at the University of Bologna, noted ridges, spirals and loops in fingerprints, which led to John Evangelist Purkinji's published thesis of 9 different fingerprint patterns in 1823.



This is a contract with a hand-print on
it, preventing the signee from going
back on his contract.

 The use of fingerprints on all contracts first began in July of 1858. A man named Sir William Herschel, in India without any thought about identification, had a local businessman stamped his handprint on the back of a contract, in hopes of scaring the man into not changing his mind about signing the contract. Since then, he required the impression of hands on every contract; not long after he only required that the middle finger of the right hand was printed. After a time of the collection of so many prints, Herschel determined that identity could be determined by their fingerprints.


  


Henry Faulds



During the 1870's, Dr. Henry Faulds, in Tokyo, Japan, took up the study of "skin-furrows" after noticing the marks of fingers on old pottery. He knew how fingerprints were used for identification and moved on to create identification and method for classifying them. Faulds published his work in a scientific journal where he discussed the ways of personal identification and how to collect fingerprints with printers ink. This marked the first discovery of the collection of fingerprint for identification.



 

In 1882, Gilbert Thompson of the U.S. Geological Survey used his own fingerprints on a document to prevent forgery. This is noted as the very first known use of fingerprints in the US.



Galton's Details



In 1888, Sir Francis Galton, a British anthropologist began his observations of fingerprints as a means of identification. In 1892, he established individuality of fingerprints and the permanence of them in his book, "Fingerprints." This research was as an aid in determining heredity and racial background. Later on in his studies, he discovered that fingerprints don’t change throughout people’s lives, and that no two fingerprints were alike. He calculated that the odds of two individual fingerprints being the same were 1 in 64 billion. Galton then identified the characteristics by which fingerprints can be identified, and those which are still used today and referred to Galton’s Details.



Automated Fingerprint Identification
Sytem



Then in 1901, Scotland Yard, using Galton's observatinos, created a Fingerprint Bureau for identifying criminals by fingerprints, starting a forensic trend throughout many police forces world-wide. Only 4 years later, the U.S. military began requiring fingerprints as a means of peronal identification for every one of their soldiers, and within the next 25 years, other agencies would follow their lead to have all of their employees fingerprints collected. In 1924, an act of congress founded the Identification Division of the F.B.I. whose job it was to record all criminals' fingerprints, and keep them on file . And by 1971, the F.B.I. had processed 200 million fingerprint cards, manually.



The IAFIS



The AFIS (Automated Fingerprint Identification System) was created to scan through tmillions of fingerprints to find the criminal that is being searched for, saving memebrs of the F.B.I. the time it would have taken for them to look through all the files manually. The most modern method used is a computer-like system much like that of the AFIS, but more advanced, called the IAFIS (Integrated Automated Fingerprint Identification System). This does the same job as the AFSI, but more efficiently nd more accurately.

 

There are 3 different types of fingerprints that are used by forensics specialists: direct, latent and plastic.



These direct prints were left behind
because the hand had touched
blood before touching the surface
from which it was collected, leaving a
very obvious print.

Direct prints are those that can be seen clearly and usually occur when the hands come in contact with substances such as dirt, paint, ink or blood.



Here, latent prints are being lifted
with powder froma watrer bottle.

Latent prints (or invisible prints) result from touching the forhead or another part of the body, transfering oils and/or sweat, then touching another object. These prints are harder to see normally, so you would need to dust the print and lift it in order to observe it more clearly.





This is a plastic print in wax
from a melted candle.

Plastic prints are quite visible and are caused by the ridges of the finger indenting a soft medium such as soap, or  melted candle wax. Another unique example is the print left on greasy car parts or on the putty that is removed from the perimeter of your common window pane.

 

Techniques Used to Lift Prints (direct, latent and plastic) 

 

This is a forensic specialist dusting
for fingerprints on a black surface,
so she is most likely uing an aluminum
powder.

There are many different colors of powders, but depending on the color of surface there are certain ones you should use.



To visualize latent prints and even to lift direct prints, fingerprint powders can be used. The color of powder you use depends on the surface you are working with. When working with a white or light-colored surface, use black carbon or charcoal, but when working with a dark or black surface, it is ideal to use a light powder, like aluminum powder for example. To dust the powder on the print, use a camel-hair brush and lightly brush (so as not to smear the print) it over the area; the powders should stick to the grease (or other medium), making the print visible. You then place a piece of tape over the prints and then put the tape on a small sheet of paper, so to be analyzed later.





Iodine Fuming methods.



When dealing with plastic prints, a photograph is usually taken and several different powders are then applied directly to the print. Then, specialized paper is used so for the print to become indented in the paper, giving the forensics specialists a better way to analyze the prints. 



When trying to make latent prints visible, one common method is that of iodine fuming. The object that the prints are on must be placed in a controlled environment with a measured amount of  cyanoacrylate ester inside. When the chamber is heated, the ester starts to release fumes that, after several hours, begin to make the prints more visible. This allows the prints to then be photogrphed and copied for later use.

And when all else fails when finding latent prints, the use of silver nitrate is utilized. To expose the prints, spray the printed surface with silver nitrate, once the nitrate is dry, expose the area to ultraviolet light. This should expose the prints so they can be photographed and a copy can be made for comparisons.

 

Techniques Used to Lift Prints (direct, latent and plastic) 

 

This is a forensic specialist dusting
for fingerprints on a black surface,
so she is most likely uing an aluminum
powder.

There are many different colors of powders, but depending on the color of surface there are certain ones you should use.



To visualize latent prints and even to lift direct prints, fingerprint powders can be used. The color of powder you use depends on the surface you are working with. When working with a white or light-colored surface, use black carbon or charcoal, but when working with a dark or black surface, it is ideal to use a light powder, like aluminum powder for example. To dust the powder on the print, use a camel-hair brush and lightly brush (so as not to smear the print) it over the area; the powders should stick to the grease (or other medium), making the print visible. You then place a piece of tape over the prints and then put the tape on a small sheet of paper, so to be analyzed later.





Iodine Fuming methods.



When dealing with plastic prints, a photograph is usually taken and several different powders are then applied directly to the print. Then, specialized paper is used so for the print to become indented in the paper, giving the forensics specialists a better way to analyze the prints. 



When trying to make latent prints visible, one common method is that of iodine fuming. The object that the prints are on must be placed in a controlled environment with a measured amount of  cyanoacrylate ester inside. When the chamber is heated, the ester starts to release fumes that, after several hours, begin to make the prints more visible. This allows the prints to then be photogrphed and copied for later use.

And when all else fails when finding latent prints, the use of silver nitrate is utilized. To expose the prints, spray the printed surface with silver nitrate, once the nitrate is dry, expose the area to ultraviolet light. This should expose the prints so they can be photographed and a copy can be made for comparisons.