Well I had some information covered on fingerprinting. Let's see what DNA fingerprinting mean.
Before that just read this sample news...
On November 22, 1983 Lynda Mann 15 was found murdered only a few miles away from her home. It was not immediately evident who had committed the crime. The police were unable to come up with any leads to catch the offender, but he had left a bit of evidence behind. The killer rapist had left a small sample of his semen. Four years later on July 31, 1987 Dawn Ashcroft, also 15 years old was raped and strangled to death. The similarities between the two cases were too evident to ignore. The police believed that the same man had committed both crimes.
A massive man hunt began to find the killer, but it seemed that none of the people they interviewed were likely suspects. The policemen got a break when some one mentioned that a young dishwasher was a possibility.

The dishwasher was subjected to a lengthy police interview. At first he denied any association with the crime but after extensive questioning he admitted to the crime although his testimony was incoherent and often contradictory. Although he admitted to the murder of Dawn Ashcroft he would not admit to the murder of Lynda Mann. At this point one of the policemen had an inspiration. He had read in a magazine about new forensic technique called DNA fingerprinting. It had not been used to solve a case yet but it seemed like a good chance to prove the dishwasher`s guilt. The technique was developed by English geneticist Alec Jeffreys. It enabled the investigators to compare the suspect`s DNA with the DNA from the semen found at the crime scene. After the results came in, the police were surprised to see that the DNA testing proved that the dishwasher was innocent of both murders. However, they realized if it could prove one man innocent it could prove another`s guilt.

A massive DNA fingerprinting of every person who could have committed the crime or did not have a strong alibi began. Months passed and hundreds of DNA fingerpints were taken from blood samples and given to the neighbourhood police, but none of them matched the semen found on the bodies of the two girls. Then the big break came. A young woman who managed a local bakery mentioned she had overheard a man confessing to another that he had paid someone to go in his place to give blood in his name. The man was named Colin Pitchfork. Pitchfork had a record and had been arrested several times for indecent exposure. The police confronted Colin Pitchfork with the murder accusations and being convinced that the DNA identification would show up positive, Pichfork admitted to both crimes. A DNA sample was taken from Colin Pitchfork and it was a match. He was guilty of the rape and murder of both girls.

             So now you can see that it is easy to prove the innocence or guiltness of an individual. So what is DNA fingrprinting?
I will just cover the basic details of it.
DNA
Deoxyribonucleic Acid (DNA) is fundamental building block of all living matter. Functioning as the "blue print" for living structures, DNA is present in all cells and most virii. DNA carries all the information needed for protein synthesis and replication of cells. In living organisms DNA is organized in chromosomes and is located in the nucleus of each cell.
Structure

DNA has a unique structure that consists of two chains like strands arranged in a twisted ladder double helix form. The sides are made up of alternating sections of phosphate and a sugar called deoxyribose. The inner strands are pairs of thymine (T) with adenosine (A) and guanine (G) with cytosine (C) These bases are the letters of the DNA alphabet using a language of genetic code.
 
Each person`s DNA code has about 3 billion loci (or places) that tell us all our traits. Because all of us belong to the same species, a large amount of our DNA codes are identical. Traits we have in common such as ten fingers and toes have identical DNA codes. Our unique differences are produced by unique DNA codes. Each person has a difference at 10 million spots along the DNA strand. One in every three hundred loci will be unique. These unique places are called DNA markers and are used in Forensic science to identify people.
 DNA Fingerprinting

DNA Fingerprinting is a method of identification that compares fragments of DNA. With the exception of identical siblings, the DNA of each person is unique. That is why it is so valuable as a form of identification.

1. A DNA fingerprint is constructed by extracting the DNA from a sample such as hair, blood, saliva or a tissue sample.

2. Isolating the DNA in question from the rest of the cellular material can be done chemically, by using a detergent to wash the extra material from the DNA. It also can be done mechanically, by applying a large amount of pressure in order to "squeeze out" the DNA.

3.The sample is then segmented or cut up using restriction enzymes.

4.The DNA is then poured into a gel, such as agarose, or onto a sheet that has been coated with this special gel.

5. An electrical charge is applied to the gel, with the positive charge at the bottom and the negative charge at the top.This process is called electrophoresis. Because DNA has a slightly negative charge, all the DNA will be attracted towards the bottom of the gel. However, the smaller pieces will be able to move more quickly and thus farther towards the bottom than the larger pieces. The different-sized pieces of DNA will therefore be separated by size, with the smaller pieces towards the bottom and the larger pieces towards the top.

6. The DNA must be denatured, so that all of the DNA is rendered single-stranded. This can be done either by heating or chemically treating the DNA in the gel

. 7. The DNA must then be blotted. The gel with the size-fractionated DNA is applied to a sheet of nitrocellulose paper, and then baked to permanently attach the DNA to the sheet.

8. The sample is now ready to be analyzed. A picture showing the DNA pattern can be developed by taking an X-ray photo. If the two patterns from the two DNA samples match, they very likely came from the same person.