Almost every day has a program on television that deals with the use of forensic sciences, and DNA, to solve crimes. "CSI," "NCIS," "Law & Order" and "Cold Case" all have someone in the cast who deals with forensic science to solve cases. Although these television shows are fictitious, they are based on fact and how science is used to solve criminal investigations. One of the most effective tests used is DNA fingerprinting. It is a very effective way of identifying an individual, but it is not foolproof, and good judgment should be used before introducing it in a legal case.
Cannot Be Altered
Fingerprints can be altered and are only on the fingers. Burning or cutting a finger can change the make-up of the print. A DNA fingerprint is identical for every part of your body, whether it is your brain, kidney or foot. It cannot be changed, so it will be identical no matter what is done to a body.
Using fingerprints requires that you get a print from a finger--no other body part will work. With DNA, all you need is a few cells from any part of the body. A strand of hair, saliva from the mouth,or skin cells from the hand all have the same DNA.
According to the Federal Bureau of Investigation, the odds of two people having the same DNA is about 50 billion to 1. Because of this, the certainty of using DNA to identify someone is virtually foolproof. To identify individuals, a scan of 13 DNA regions, or loci, is conducted. The data then is used to create a DNA profile of that person, called a DNA fingerprint. It is fairly common to match a few of these regions but virtually impossible to match all 13.
Although DNA fingerprinting is very accurate, it also is very sensitive and can be contaminated easily. According to the Woodrow Wilson Biology Institute, the slightest contamination can affect the test, and it is difficult to keep a sample contaminant-free. Also, if different people or equipment are used to measure the length of the DNA sequences, they might get different results. As of 2010, there are no standards for labs, nor any kind of licensing requirements. This could lead to poor test quality and reliability.