This research examines the use of deoxyribonucleic acid (DNA) testing in criminal investigations. Nucleic acids are the sole vectors of genetic information. They are polymeric molecules, of which the structural unit is a nucleotide. The nucleotide is one of two types of compounds. Each type of compound includes a nitrogen-containing base and a phosphoric acid. The first type of compound also contains a ribose sugar in ribonucleic acid (RNA), while the second type of compound contains a deoxyribose sugar in deoxyribonucleic acid--DNA.
In criminal investigation applications, DNA testing is often referred to as DNA fingerprinting ("DNA sample offer accuracy," 1990, January 1, p. B1). The preferred term among experts, however, is DNA typing (Boyd, 1990, May 13, p. B1). The terms genetic fingerprinting and genetic typing are also used.
DNA fingerprinting is a "time-consuming and complicated process" ("DNA samples offer accuracy," 1990, January 1, p. B1). It is, however, the "only foolproof method of biological identification" (p. B1). Every living cell in a human body contains DNA strings. "The pattern, length and number of the repetitive DNA is different for each individual" (p. B1).
The methods and procedures required to isolate DNA components (and, thus, make DNA fingerprinting possible) were developed in the early-1980s (Lynch, 1990, November 5, p. A4). The methods and procedures were developed in Great Britain (Jenkins, 1990, July 15, p. C3). Blood and tissue samples are best for use in DNA testing. Any organic material from a human body, including hair, saliva, semen, and skin, however, may be used. The DNA fingerprinting analysis compares the DNA structures in evidence gleaned from a crime scene with samples taken from a suspected individual.
Obtaining a DNA fingerprint is an 11-step process ("DNA samples offer accuracy," 1990, January 1, p. B2; Miller, 1990, August 12, p. B2). These steps are as follo...