Deoxyribonucleic acid, commonly referred to as DNA, stores genetic information about people at molecular levels, biologically speaking.
Due to the efficiency of DNA in its storage of genetic data, and growth of the scientific technology which simplifies the process of matching DNA samples to their respective donors, it has become an important evidentiary tool for law enforcement investigations.
Deoxyribonucleic acid and Criminal Cases
Although traces of a suspect’s deoxyribonucleic acid may have been found at a crime scene, this doesn’t necessarily mean a lock, stock, and barrel conviction for the district attorney and the prosecution. 
Even though the potential of DNA to identifying a suspect is akin to a fingerprint being collected and admitted into evidence, any good criminal defense attorney will tell you that crime scene investigators and detectives have to take measures to ensure that the collected DNA evidence has not become contaminated or else it may be useless at trial.
Potential Crime Scene Sources of DNA Evidence
DNA can be obtained at a crime scene by forensic investigators from the following sources;
- Bodily Fluids,
- Hair, Blood, Skin, and Saliva.
- Mucus, Spit, Urine, Semen, Skin, Skin Cells, Fingernails,
- as well as clothing, eating utensils, cigarette butts and more.
In cases involving murder, biological evidence which can be used to identify the perpetrator is normally found on or near the murder victim. However, it may not mean that they have identified the right person, or that the person identified is the one who committed the criminal offense. As with the case of Josiah Sutton, the Houston Police Department’s crime lab has been known to taint evidence, improperly process it, or not process it at all.
DNA can either free a defendant, or convict them in the court of law. When DNA is collected, its usually added to the nation DNA registry called the CODIS (Combined DNA Index System). If you are facing a criminal case in Houston, Texas then you may want to consult with a criminal justice lawyer about helping you fight the State’s case against you.
