DNA Profiling – From CSI to the Courtoom

I’m taking a break from talking about serious law issues to discuss a fundamental development in the field of criminal investigation since the 80s that has direct ramifications to the legal community. This is DNA profiling, and its a subject I’ve been immensely interested in ever since I got hooked on to CSI.

The main purpose of DNA Profiling is to increase the strength of the evidence in the courtroom – any lawyer’s wet dream, perhaps.

Beginning in the last 1980s, DNA profiling became a widespread and reliable method to substantiate the evidence provided in a case. DNA profiling relies on the signature genetic makeup of a person. In addition to our unique fingerprints, each of us also possesses a unique identifier that is built within our bodies – the DNA (deoxyribonucleic acid) which determines all our biological characteristics, from our physiology to our psychology.

DNA is a long, double-helixed molecule located in almost every cell in the human body. Half of our DNA is inherited from our mother, the other half from our father. All human beings are almost 99.9% identical; the remaining 0.1% is enough to give each of us our uniqueness. Humans even share 98% of their DNA with primates such as chimpanzees and gorillas.

The DNA is made up of about 3 billion base pairs which are composed mainly of carbon and sugar. These are the building blocks of DNA. The 3 million (0.1%) base pairs that are unique to each individual.

Since the 80s, courts have become increasingly reliant on DNA profiling to sift through evidence. DNA profiling, also called DNA fingerprinting, has proven to be highly reliable, and investigators can comb out the DNA from very old and deterioated samples, enabling cases as old as 30 years old to be solved.

We’ve all seen it on CSI. A sample of a suspect’s DNA can be enough to nail him down. In fact, it was CSI that made me so interested in this field which in intrinsicly related to the field of law. Pretty much anything can be used to extract DNA: hair, blood, bodily fluids. These DNA tests can be a boon (or bane – depends on which side you’re on) in criminal as well as civil cases. Issues of paternity are the first ones to be settled by DNA tests, and many a marriages have been saved because of DNA profiling. In the context of statistics, DNA profiling is largely used in sexual offence cases (almost 60%), homicides (20%), assaults (7%), robbery (7%), and other cases (6%). As attorneys, proper DNA evidence can make your life in the courtroom a whole lot easier; the courts virtually consider DNA as foolproof evidence.

WikiPedia has an unusually strong article about DNA Profiling. I suggest you read it if you want detailed information about it.