The first journal is entitled: “DNA Evidence: What Law Enforcement Officers Should know. ” It is a collection of the basics of DNA Evidence and it shows the things that officers in the field should know and exercise. Obviously, the name suggests what law enforcement should and should not do in handling DNA evidence. The manner of proper handling results in either a conviction, non-conviction or a wrongful conviction. (NIJ, 2003) The proper procedure in handling DNA evidence is crucial. The journal divides the handling into phases. First, there is crime scene procedure.
Second, there is collection and preservation. Third there is elimination of samples. Fourth, there is evidence transportation and storage. Last, there is DNA testing. At the crime scene, one must realize that there are a wide variety of biological evidence present. This means that evidence, even though not visible to the naked eye, can be present. An example would be saliva, semen, hair, and even blood samples in a sexual assault. These samples can be located at various spots in the crime scene including carpet, mattresses and other surfaces.
These samples are compared against the DNA of the victim, suspect or other potential suspects who may have had access to the scene. Another way is to compare such samples with CODIS or the Combined DNA Index System to identify a suspect or to link serial crimes. During Collection and Preservation, officers take to mind that proper collection is needed for a successful testing. Contamination is a key factor to watch out for. DNA evidence can be contaminated by even sneezing or coughing over the evidence.
The journal article contains a list of items to follow in order to avoid contaminating evidence. This list includes wearing gloves, using disposable instruments, avoiding touching any area where DNA might exist and even air-drying evidence thoroughly before packaging. All these are taken to mind because proper documentation and preserved DNA evidence will be given increased weight in court. In elimination of samples, the officers would compare the DNA found in the crime scene to those who might have had access to the scene.
DNA evidence from these people would be compared to that found in the scene of the crime. As such, suspects can be eliminated. In rape cases, investigators may need to collect and analyze the DNA of every consensual sexual partner the victim had up to 4 days. Extreme sensitivity must be made when approaching the victim to get the required information. In transporting and storing these DNA evidence, great care must be given to avoid spoilage. Once again, contamination is at issue when tackling storage and transportation means. DNA evidence should be kept dry and at room temperature.
It should be place in paper bags or envelopes and then sealed, labeled, and transported in a way that ensures proper identification and documents a precise chain of custody. This means that the officers know where and when the DNA passed through before its testing or presentation in court. Direct sunlight, heat and humidity also harm DNA evidence. In DNA testing, the most common way to do such test is by way of polymerase chain reaction (PCR) technique. Polymerase is an enzyme involved in the natural replication, or copying of genetic material.
A small amount of DNA evidence can be replicated using this technique in order to be capable of being tested. However, if the DNA evidence is contaminated, the replication process will include this contaminated amount. In such cases, the evidence will most likely lead to inconclusive findings. As can be seen from the article, the proper collection, handling and testing of DNA evidence is crucial. If this is not done, the evidence may be contaminated. Contaminated DNA evidence holds little evidentiary weight in court.
As such, in response to our problem, we see that a properly collected DNA evidence would lead to conviction while contaminated evidence will lead to non-conviction and at worst wrongful conviction. The problem of wrongful conviction arises when contaminated DNA evidence is given much weight in court. This arises when the officers of the court trying the case are not well-versed with the technology. This happens when a judge improperly admits DNA evidence or when a defense attorney fails to note the probable contamination that has happened in the course of the investigation.
Our next article addresses this issue by suggesting online DNA training to target lawyers and judges. (Schmitt, 2007) The article recognizes that in today’s criminal justice system, DNA evidence is such a powerful tool that it must be carefully wielded an properly understood. DNA technologies, techniques and analysis presents new challenges to prosecutors, defense lawyers and judges. The article coined the term “CSI Effect” to explain the current increased expectations of jurors that forensic science will solve an increasing number of cases.