Dna Analysis: Validity And Doubts
Essay by 24 • September 18, 2010 • 600 Words (3 Pages) • 1,917 Views
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
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