Criminal DNA Testing

DNA or Deoxyribonucleic acid refers to the genetic material in the cells of a human body. Every human being receives half of the DNA from the biological mother and the other half from the biological father. With advances in technology, DNA evidence has become a vital forensic technique to identify criminals when biological tissues are found at the crime scene. A single hair root, saliva, blood or semen can help in the identification and conviction of criminals. Sweaty shirts, fingernail clippings, urine, chewed gums, used tissues and licked stamps can also be used for testing. DNA can be used to make the portrait of a probable suspect. DNA evidence is also useful in determining skin color and eye color. DNA fingerprinting, which is also known as genetic fingerprinting, is a very important tool in the identification of criminals.

The majority of DNA of one person may match the DNA of another person. This makes the process of differentiation between two people extremely difficult. Microsatellite is a particular type of DNA sequence that simplifies the process of identification. Microsatellites are small pieces of DNA that occur repeatedly in a person's DNA. They tend to vary in a particular area and their comparison helps in identifying a person quite effortlessly.

It is almost impossible to eliminate all the physical traces of a person's presence at a place of crime. A single cell is sufficient to identify victims even in situations where the body is completely destroyed. DNA fingerprinting is not accurate as a regular fingerprinting process but it does provide some clue to begin an investigation.

In post conviction cases, DNA testing also helps attorneys prove a client's innocence. In cases where the biological evidence was collected but DNA testing was not carried out, the evidence can be subjected to DNA testing to absolve the client. In cases where biological evidence was never collected or biological evidence was destroyed, post conviction on the grounds of DNA testing is not possible.