DNA stands for deoxyribonucleic acid. It is defined as the fundamental “road map” of an individual’s entire genetic makeup. It is essentially a roadmap of every cell in the human body. DNA can be found in sweat, bone, the root and shaft of a hair follicle, skin tissue, earwax, spit, urine, semen and blood. Any DNA that is collected from the crime scene is used for evidence about who committed the crime, not to determine physical characteristics.
In a criminal hearing, DNA is a useful tool because it can both exonerate and implicate a suspect. No two people have the same DNA, except in the case of identical twins. That is why DNA evidence collected at the crime scene can link a suspect directly to a crime or eliminate a suspect altogether. DNA can also be used to identify victims of homicide.
The most common DNA evidence found at crime scenes is from saliva, blood, hair, skin tissue or seamen, and is essential to the investigation of sexual assaults and other violent crimes. DNA that is properly collected from the victim, crime scene or suspect is then compared with other samples in order to connect the suspect to the crime scene.
It is virtually impossible to deny DNA evidence in court unless it is assumed that it has been planted. Because DNA profiling is widely believed to be almost infallible, cases are often brought with little corroborating evidence. But, unless other evidence points to the defendant, the DNA profile still leaves a one third chance that a suspect is innocent despite the exactness of the match.
DNA evidence was first allowed back in 1990. It has virtually changed the face of the criminal justice system. Relying on DNA evidence and focusing on just the physical evidence can downplay even the basic elements of a trial such as the motive, the police investigation, presumption of innocence, and implications of reasonable doubt. DNA evidence in murder or rape cases often influences the jury and has an effect on verdicts. They are the kinds of cases that are reported on most and often highlighted in the national media.
Important aspects concerning a case, such as motive, should not take a back seat to physical evidence. For example, what if a man finds out his wife is involved with a neighbor and he becomes so enraged that he kills her. Then he plants DNA of the neighbor at the scene. The police find it and now the neighbor is under suspicion. The question that needs to be raised is: how did the DNA get there? Is there room for doubt? Just because physical evidence is found doesn’t mean that the suspect is automatically guilty. DNA evidence can be improperly handled or even planted. That is why it’s extremely important to gather all of the information regarding a criminal case and not just rely on DNA evidence. Though it is vital to criminal cases, DNA should always be weighed against the other evidence in the case.