Methods Used to Lift Fingerprints from Surfaces:

Powder And Tape: This is probably the most well-known method of detecting latent prints. A variety of powders are used in dusting for prints, many containing either aluminum or carbon. This finely crushed powder is gently applied to a surface, and the small particles of powder stick to the residue that the print leaves, making it visible to the human eye. These prints are then lifted using tape. For dusting to work, the surface that is being dusted must be completely dry and relatively free of other contamination.

Magna Brush: This is a magnetic wand that attracts iron. It is dipped in iron dust, and the particles cling to it. This is then used the same as dusting using carbon and aluminum powders. The Magna Brush is also less messy, as any excess iron particles can be easily collected with the Magna Brush. There are many colors available for this, and some of these powders reflect alternative light sources such as UV and lasers.

The Cyanoacrylate Fuming Method: Also known as the superglue fuming method, the cyanoacrylate fuming method has proved to be another very useful way of detecting latent prints. This method was first used by the Criminal Identification Division of the Japanese National Police Agency in 1978. Shortly after this it was adopted in the US, and now it is a commonly used method of detecting prints. They basically use super glues to do this process. This reacts with the traces of amino acids, fatty acids, and proteins in fingerprints as well as the moisture in the air, making them visible.

Ninhydrin:Another common method of fingerprint detection is the use of ninhydrin. This is sprayed, swabbed or dripped onto the surface. Ninhydrin reacts with the amino acids in the prints, forming a purple or pink compound.

Iodine Fuming: Iodine crystals are placed in a glass tube known as a fumer. The examiner then blows into the fumer, causing the transformation from solid to gas. The iodine vapours are emitted from the other end, and if the tube is aimed at a latent print, it will become visible for a short time.

Silver Nitrate: Silver Nitrate is a less toxic way of detecting prints on paper. Silver chloride turns black in light, and one of the components of sweat is sodium chloride. The silver nitrate is placed with distilled water and applied to the paper. The paper is exposed to light, and any prints will turn black.

Types of Patterns:

People may have many of the same general patterns, but never the EXACT same pattern. There are 8 major types of finger print patterns. These eight patterns are put into three categories: Arch, Loop, and Whorl.

Arch:

Plain Arch: Plain arches have line across
the finger that runs smoothly from one
side to the other. There is no upward
thrust like the tented arch.

Tented Arch: Tented arches have lines
across the finger that thrust upward.
They are called a "tented" arch because
the pattern resembles a tent.

Loop:

Radial Loop: The radial loop makes a
downward loop that goes from the
pinky to the thumb.

Ulnar Loop: The ulnar loop makes a
downward loop that goes from thumb
to the pinky.

Whorl:

Plain Whorl: Plain whorls have
circles coming from the middle
of the finger.




Double Loop: A double loop has
two sets of loops on the finger.




Accidental: Accidental whorls have
a mix of patterns.

Types of Finger Prints:

There are three major types of prints people leave on surfaces. These three would be:

Latent:

You cannot see latent prints with the naked eye.

They are formed from the sweat from sebaceous

glands on the body or water, salt, amino acids and

oils contained in sweat. The sweat and fluids create

prints must be developed before they can be seen

or photographed. They can be made sufficiently

visible by dusting, fuming or chemical reagents.

Plastic:
Also known as impressed prints, plastic

prints are indentations left into surfaces

that are soft such as clay, paint, wax, etc.

They do not need to be developed; you

can see them right on the surfaces.

Direct:
Direct prints can be seen right on surfaces

without any modifications. Most times

these prints are photographed instead of

lifted so that you don't risk messing up the

print. You can often find these fingerprints

from ink, dust and blood.

History of Fingerprints

In 1852 fingerprinting was first used simply on contracts to look at them and the patterns they made. They weren't studied for scientific beliefs, but for superstitious beliefs. But soon a man named Sir William James Herschel connected the fact that you can prove or disprove identity with fingerprints.
Since then, there have been discoveries through ink impressions. People have even signed papers with their names along with a thumb print to prevent forgery. Then Alphonse Bertillon came along and said that fingerprints could measure how big your hand is and how long your arm is. However, this was proven that is couldn't necessarily always work.
Now fingerprints are still used to this day to solve crimes, identify criminals, and record data. They play an important role in science and the rest of society.