DNA IN CRIMINAL INVESTIGATIONS

DNA in Criminal Investigations

DNA in Criminal Investigations

DNA can be found in almost any bodily fluid (semen, saliva, blood, etc.) and in less obvious places such as a strand of hair. It has become a crucial part of investigating crimes, and will continue to develop this way. DNA first came into use for forensic science in 1986. It was used by a scientist by the name of Alec Jeffreys and his colleagues from Leicester University. He was contacted by authorities to verify the confessions by a seventeen year old porter regarding a double rape-murder case. As it turns out, this boy proved to be "the first murderer to be cleared as a result of DNA fingerprinting".

DNA can be found in such things as blood and semen. It can also be found in such things as tissue found beneath the fingernails of a victim after a struggle, it can even be found in saliva cells left on a mouthpiece of a telephone after a conversation. DNA is everywhere in a persons body, and can not be replicated. It is unique to every person, but all blood relatives have similar qualities that make them identifiable. DNA stands for deoxyribonucleic acid, and it basically looks like a twisted ladder, or a double helix with rungs or base pairs. Guanine (G), Adenine (A), Thymine (T), and Cytosine (C) are the four bases that make up the base pairs. The bases don't just pair with any other bases, there are certain predictable combinations: A with T and G with C, and these are true to any DNA. The human body contains in excess of three billion base pairs, only a few of these are what attract forensic attention. [Rob, 1995]

On January 22, 1986, Robert Melias became the first person to be convicted of ...