DNA Analysis: Validity And Doubts

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DNA : Criminal Identification
Validity and Doubts

DNA, although controversial on accuracy, has provided a new means of

identifying criminals where there is little physical evidence. This allows you to take a

piece of hair, a spot of blood, or skin tissue and make a positive identification on a

suspect. Since it's first use by the FBI in December 1988 it has grown to become a major

factor in criminal investigation. This new key gives them help when the crime scene

lacks evidence. DNA evidence also allows detectives to narrow down suspects and keep

innocent people from being prosecuted.

In 1990 the FBI began development of a national DNA identification

index. The FBI has received over 10,000 submissions of DNA evidence from police

agencies and DNA evidence has been used in over 500 cases throughout the United

States. The FBI performs testing for free to all police agencies to help keep costs down

in prosecuting criminals. More than 50 laboratories perform DNA analysis around the

US. The chances of two people having the same DNA profile is 1 in 50,000 all the way

to 1 in 5 million according to scientists estimates.

DNA controls all our inheritable information like eye color, hair color,

skin color, etc. DNA differs in all people except for identical twins. All cellular matter

contains DNA: this includes white blood cells, bone cells, tissue cells, spermatozoa, and

hair root cells. Adenine, thymine, guanine, and cytosine are the building blocks of DNA

strands which make up the letters of a genetic code. In certain regions of a DNA strand

the sequence of genetic code is unique which allows scientists to identify an individual

and exclude others.

The FBI, Cellmark, and Lifecodes are the 3 major laboratories that courts

accept DNA profiles from. As estimated by the FBI, the chances of two DNA samples

being the same is as low as one in a trillion. Critics of DNA say that the FBI has falsely

applied theories of population biology behind it's calculations, so courtrooms make DNA

seem inaccurate. More than half the states have a mandatory DNA testing of all people

convicted of sexual charges and violent offenses, to help in future criminal investigations.

Although some people say that this is an invasion of privacy, it's a good way to prosecute

repeat offenders and find suspects when only DNA evidence is available.

As accurate as DNA profiling is, there are still many questions about the

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