Expert Advocates Greater Use of DNA


Head of the Department of Basic Medical Sciences at the University of the West Indies (UWI), Mona, Dr. Wayne McLaughlin, has advocated greater use of Deoxyribonucleic Acid (DNA) evidence, to help solve crimes in the country.
Making his presentation entitled, ‘DNA: Solving Crimes the Scientific Way’, at the Jamaica Young Scientists Forum (JYSF), held at Jamaica House on May 28, Dr. McLaughlin referred to DNA as “the molecule of life,” which carries the genetic information that makes up the genes (hereditary material) in humans and almost all other organisms.
He explained further that DNA evidence is one of the components of forensics or forensic sciences, a term which applies to legal investigations. He argued that DNA evidence is a “genetic witness,” that is objective, scientifically valid and reliable.
Forensic science can be defined as the practical application of numerous sciences in gathering and analysing evidence to establish facts for the purposes of the law.
“Forensics look at the detailed analysis of past events, so (it is) based on evidence that you collect, in terms of trying to figure out what happened in the past,” Dr. McLaughlin said.
The Department Head is also Director of Caribbean Genetics (CARIGEN) at the UWI, an independent, state-of-the-art DNA testing laboratory, which offers a wide range of DNA testing services. The laboratory has helped to solve several crimes in Jamaica. It also carries out work for both the defence and the prosecution, during court cases at times.
In terms of the forensic tool of DNA in solving crime, Dr. McLaughlin noted that DNA can be used to exonerate the innocent. He pointed to a case that CARIGEN worked on in Jamaica, where, after spending almost four years in jail, an accused person was freed of rape when DNA evidence proved his innocence.
He noted further that DNA evidence has also been useful in identifying the remains of missing persons, such as in the case of Ananda Dean, which CARIGEN also worked on, that involved the 11 year-old girl, who disappeared on her way home from school last September, and was later found dead.
“We (CARIGEN) did the work on that. Essentially, we had only bones to work with, so it was really difficult, but we were able to identify that the body was Ananda Dean,” Dr. McLaughlin said.
Forensic evidence has also been used in identifying victims of mass disasters, such as the victims of the September 11, 2001, World Trade Centre attack in the United States (US). “A lot of the identification process was done using forensic DNA techniques,” he pointed out.
As forensic DNA is based on the Locard’s Principle, that ‘every contact leaves a trace’, Dr. McLaughlin informed that this principle is also useful when applied to sexual assault cases, where the wrong-doer either leaves signs at the scene of the crime, or takes something from the scene.
“So, when that person is apprehended, they usually look for traces of hair, for example, which is quite typical in a rape case, and you can actually link it back to the scene of the crime,” Dr. McLaughlin explained.
Other cases where DNA evidence has been successfully used include homicides, minor crimes and property crimes. Some of the samples usually collected at crime scenes are: blood and blood stains, semen and semen stains, bones, teeth, saliva, debris from fingernails, cigarette butts, fingerprints, personal items, such as tooth and hair brushes, and razor blades.
Dr. McLaughlin noted however, that DNA is not the magic bullet. “You can’t solve every crime, because a lot of it is that you have to depend on other evidence to support the DNA evidence. People might think, ‘oh, once you have the DNA, that’s it,’ but really, that’s not true, you need other facts,” he stressed.
He pointed to other applications for DNA testing, most of which are done at CARIGEN, such as identifying endangered and protected species; parentage testing; genealogy; authentication of meats, wine and caviar; military DNA; and determining the pedigree for seed or livestock breed.
Spearheaded by the National Commission on Science and Technology (NCST), the Jamaica Young Scientists Forum (JYSF) was established in January 2002 to facilitate networking and collaboration among young Jamaican scientists and technologists and to foster youth participation in science and technology activities, geared toward individual and national growth and development.
The Forum, themed: ‘Networking Youth in Science and Technology for a Better Jamaica’, was incorporated under the Company’s Act as a Limited Liability Company on August 9, 2005, to function as a Non-governmental entity.

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