Most people’s exposure and understanding of DNA evidence comes from television shows, books or brief news stories. DNA evidence is not used, or even attempted to be obtained, in the overwhelming majority of cases. However, there are criminal cases where DNA evidence can be a critical element to the case.
In a recent armed robbery and battery case near Jacksonville, Florida, a convenience store was robbed by two people wearing masks. They jumped into a vehicle that later crashed. The police found the crashed vehicle, and recovered the masks inside. The police were able to obtain DNA from the masks.
At the trial, the state’s expert testified that the DNA of at least two individuals was recovered from the masks. The expert compared sixteen genetic markers and performed an analysis on the results. He testified that the defendant could not be excluded as a contributor of the DNA in one of the masks as fifteen of the sixteen genetic markers matched the defendant. However, due to the limited DNA that was recovered, the expert was not able to do a full analysis of all of the genetic markers. The expert testified there was a 1 in 2600 chance that an unrelated male of the same race contributed the DNA.
The criminal defense attorney filed a motion to prevent the DNA testimony from being presented to the jury. The criminal defense attorney argued that because the full DNA analysis was not performed, the evidence was not sufficiently reliable to be admissible at the trial. The idea of DNA evidence can generally carry greater weight although the complicated details may be less certain and misunderstood by a jury.
The judge in a criminal case has a lot of discretion in determining what evidence is relevant and admissible so that it can be presented to the jury. In this case, the judge found that the DNA evidence was reliable enough to be admissible. As a result, the defendant was convicted on the armed robbery and battery charges.