Forensic DNA analysis has proved to be a very powerful investigative tool used by law enforcement to solve crimes. However, compared to other forensic disciplines such as Latent Fingerprint analysis and Controlled Substances analysis, Forensic DNA analysis is a newcomer to the Forensic Sciences. Reaching slightly beyond the twenty year mark, Forensic DNA analysis has probably observed more change and scientific advances than many of the other disciplines in application today.
DNA, also known as deoxyribonucleic acid, is the primary building block of life. It provides a genetic blueprint that defines an organisms individual traits and characteristics. Forensic DNA analysis breaks open an individual's genetic code and enables the forensic scientist performing the analysis to examine certain locations (loci) of the DNA to distinguish one individual from another. It is the basic understanding of Forensic DNA analysis that:
1.) DNA is inherited from an individual's biological mother and father. Only identical siblings can have the same DNA. There are only similarities in the DNA of related individuals.
2.) DNA can be found in the nucleated cells of the body and is the same for each individual. Therefore DNA is the same in your blood, hair, bone, saliva, etc.
3.) DNA doesn't change over time. As you get older your DNA doesn't change to a different profile.
4.) DNA is relatively stable under optimal environmental conditions. Certain factors such as heat, light, and moisture can degrade DNA, however the processes used for Forensic DNA analysis are very sensitive and can detect DNA in very small quantities.
Forensic DNA analysis can be very useful in an investigation especially if the crime is of a serious and aggravated nature such as homicides and sexual assaults. Many of the crimes investigated which contain Forensic DNA evidence are generally perpetrated against individuals and therefore various DNA containing bodily fluids are left behind.
Forensic DNA analysis, although used the majority of the time to convict an offender, can also be used to exonerate an individual. Many cases in recent years have used DNA evidence to set an incarcerated individual free, due to the advances made in the science. What was once considered limited evidence prior to DNA testing is now undergoing DNA testing to determine guilt or innocence.
DNA evidence is very reliable evidence in an investigation due to the information it provides. It adds another piece to the puzzle and it is up to the investigator to utilize this information in the best way possible.