DNA has been an increasingly important part of forensic science and crime solving in the last few decades. Since DNA differs between each individual, a person can be linked to a crime based on the genetic information that is found at a crime scene. This generic information can also be used as exculpatory evidence to clear an individual’s name from the list of suspects. Similar to the use of fingerprints, investigators collect blood samples as well as saliva, hair and any skin that may be under a victim’s fingernails. These samples are then tested for the DNA information and can also identify a victim to the relatives in the event that nobody can be located. Once the DNA evidence is in the computer system, this information can be connected to crimes in other areas of the country as well. This is especially useful for similar crimes that occur at different locations which may or may not be caused by one person.
DNA can be tested from teeth, fingernails, urine, mucus, perspiration, and other bodily fluids; this valuable DNA information can be found on evidence from decades prior to the investigation. Environmental factors can affect DNA, so every piece of DNA that is found cannot always be used as part of the profile. The tests from the DNA cannot indicate how long age the suspect was at the crime scene, it can only determine whether or not the suspect was there.
Since forensic technology has advanced so much in recent years, police are reopening cold cases to further analyze any possible DNA evidence left over from the original investigation. Not only has the emerging technology put criminals in jail, but it has also exonerated many people who had been serving time for a crime.
Three examples are: In case of murder, if the murderer left his own blood stains in the close vicinity of the scene, then the DNA samples obtained from those stains can be compared to those DNA samples that are taken from the suspect. 2. In case of rape, the semen found presumably near the...