DNA & Crime- VRG

Summary--

As i think this is the very usefull invention in the crime investigation. DNA databaes is alao known as DNA fingerprints. A British scientist,Alec Jeffreysinvented this technique of using DNA samples to extract the unique marker. this technique is then used for the maching the DNA structure of criminals.
DNA profiling :-
DNA- Deoxyribonuclicacid, genaraly found in every cell of body. Only the samples like seman, blood, saliva is for analysis of the DNA. It can not shows the genetic disorders or any other kind of disease.
DNA in crime detection:-
The NDNAD (National DNA Database) is a database used by the police that contains DNA data stored in a computer andstored samples from the scenes of crimes as well as from people who have been arrested, acquitted or convicted of a crime. The DNA from every sample is analysed in a limited number of areas to produce a 'DNA profile' for each individual or sample from the scene of a crime.The database relies on the fact that every person's DNA is unique (unless they are an identical twin) and that the chance of an identical match between the DNA sequence taken from two different people is very low – less than one in a billion if they are not related. However, it is possible to get 'false' matches and the chances of a 'false' match are increased (i.e. the wrong person is identified) if samples are obtained from people who are related or if the DNA profile is incomplete. Incomplete profiles are often obtained from scene of crime samples because the DNA is often degraded. Following collection and analysis of a sample, a new DNA profile can be compared with the profiles stored on the database. A match can arise in four different ways. If:
1. a new scene of crime profile matches the profile of an individual already on the
database. This can help to identify a potential suspect very easily;
2. a new individual's profile matches a stored scene of crime profile from an unsolved crime
or crimes on the database. This type of 'speculative search' can identify a potential
suspect long after a crime has been committed;
3. a new scene of crime profile is found to match that of an old crime scene. This can help
the police in their investigations even if a suspect is not identified; and
4. the person has been sampled and included on the database previously under the same
or a different name.
Therefore, DNA profiling is a powerful tool in solving many serious crimes and deterring
serious criminals. In a typical month, matches are found linking suspects to 30 murders, 45
rapes and 3,200 motor vehicle, property and drug crimes.

Possible Errors in DNA profiling:--
In some cases DNA evidence can be difficult to analyse, particularly when
samples from the crime scene are destroted or contain more than one person's DNA.
Currently, the criminal justice system may not always take sufficient account of the possibility
of errors and people may be wrongly convicted either by mistake or even by being 'framed