DNA Testing Breaks New Ground for Courts

DNA testing has three major applications for forensic studies: identification of missing persons; identification of victims of wars, accidents, and natural disasters; and crime investigation. Annually, more than 20,000 forensic DNA tests are performed in the UK. Two out of three of all criminal cases using DNA evidence involve sexual assault, the rest are cases dealing with burglary, murder, and other types of violent crime. During the last 15 years, DNA trial analysis became an indispensable police tool in fighting crime because it allows unambiguous identification of the criminal by traces of biological material left at the crime scene. It can also acquit innocent suspects based on DNA evidence.

Criminal justice system now relies heavily on DNA-based evidence. Since it was first used in the Enderby murder case (1986), thousands of perpetrators has been convicted of various crimes with the help of DNA evidence, and hundreds wrongfully convicted people have been exonerated

The most common samples collected at the crime scene are blood, semen, and saliva; virtually any biological material or objects handled by a perpetrator can be now used for forensic DNA testing. Clothing, furniture, and other items which may have traces of DNA, are now routinely used for obtaining DNA evidence. The technology is so sensitive that it allows identification of a person by analysing DNA collected from a fingerprint left on the surface of an object or from a single hair left at a crime scene.

When a crime scene sample or a sample from a suspect is analysed, a DNA profile is produced. A DNA profile is a digitalised representation of an individual