DNA Fingerprinting

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DNA Fingerprinting: Guilty or Innocent?

The complete three-billion base sequence of DNA, deoxyribonucleic acid, for any individual is unique, like no other human’s (except in the case of identical twins) (Browning 1). This single substance has recently been used as evidence in U.S. courtrooms. Many experts say “its [DNA] precision damns the guilty and frees the innocent” (Cheney 2). This nucleic acid’s precision develops a fingerprint, which identifies a criminal. The test to find such a fingerprint consists of two DNA samples-- one from the suspect’s blood or other body tissue and the other from the victim or crime scene. After certain tests find two sets of fingerprints, scientists look for a match between the two. If one is found, DNA exonerates the innocent and terrifies the guilty (Browning 1). Accurate, concluding genetic tests on DNA have served as great evidence to convict or free criminals throughout the judicial system.
Located in the nucleus of every cell in the body, DNA holds the basis of individuality, making the blueprint of a convicting genetic fingerprint (Froelich and Leyden 3). It consists of four chemical substances-- adenine, cytosine, thymine, and guanine (Browning 1). Adenine joins only to thymine to form one pair of bases. Cytosine joins only to guanine to make another pair. These four bases fit between DNA’s two strands which form a double helix ladder (Froelich and Leyden 3). DNA’s four organic units are arranged in a complex and unique combination in every individual’s cells. Two percent of DNA consists of a human’s genetic code which can be in any sequence of the four bases (Schefter 6). For example, each person has 23 pairs of chromosomes with about six million base pairs which are in a certain order to identify one person (Froelich and Leyden 3). With such a uniqueness between individuals, the probability that two people have the same DNA ranges anywhere “from 1 in 50,...