DNA Evidence - Research Paper Example

The research on DNA evidence started showing significant improvement by the 20th century. DNA evidence became widespread and it became a problem-solving tool for immigration disputes, refining the assay, resolving specimen identity, detecting genetic differences and identifying criminals; thus, the need for DNA identity testing became significant. Historically, DNA evidence began in the forensic field when ABO blood group was used as a system in providing evidence of crime issues. Later, the paternity identification that based on serum protein variation became commonly used.

However, it was not until when Jeffrey became a pioneer of DNA based identity testing. DNA evidence became common in federal courts, and the first DNA evidence was carried out in the court case of Andrews Vs., Florida in 1988 (Newton, 2008). Many states started adopting DNA evidence in order to identify crime issues as a way of maintaining criminal justice. DNA evidence started evolving as an effective technique of providing proof over crimes issues. It is used up to present in many areas including clinical applications for testing identity, and also solving paternity issues in case of child denial or resolving specimen identity; thus determining the origin of mishandled specimens.

The major sources of DNA evidence include semen, bone, blood, skin cells, hair, teeth, urine, tissue, saliva, feces, and vomit. First, blood is one of the main sources of DNA evidence. The substrate in which bloodstain is found can determine the DNA testing; thus providing effective evidence in case of homicide or any other crimes issues. Blood contains some substances that may hamper successful DNA testing process; thus, these substances can be removed through purification methods (Parks, 2010).

DNA profiling is the only way through which scientists can be able to stain of a given blood mixture. Through DNA testing, one can be able to determine in case specimen are from the same or different sexes. Semen is another source of DNA testing. The semen stains can be analyzed and examined as well as tested through conventional methods in order to provide the required evidence. Sperm cell staining can help in determining in case the stain is the outcome of vaginal drainage. This will enable scientists to determine the rape cases through DNA analysis of semen stains.

Moreover, body tissues, saliva and hair roots are among the major sources of DNA evidence. DNA strand isolation from body tissues can help in achieving the intended goals of DNA evidence. DNA survival can be found in teeth or dense bones. The remains of body tissues that have been scattered by either gunshot or trauma can adhere to the bullet; thus, they can sometimes yield sufficient DNA testing. There are some treated tissues by use of the chemical treatment known as formaldehyde and embalming.

DNA testing can be successful in both tissues. For instance, a body of a person killed and buried for many years can still yield better results when used in carrying out DNA evidence. Hair roots can be the legitimate source of DNA evidence, but they are not effective in regular forensic use. Saliva can be taken from penile marks, bite marks, bottles and cigarette butts found in the crime scene. Despite the exciting promise of DNA technology, DNA evidence poses some problems.