Modern DNA Applications: Who was the Driver?

DNA Expert Witness

Christian G. Westring, Ph.D., Forensic Geneticist
The advent of DNA testing for forensic science applications has revolutionized the breadth and scope of how investigators can successfully use modern DNA testing to help solve a wide variety of cases. While DNA evidence is usually not enough to solve a case on its own, DNA is generally regarded as the gold standard among forensic practitioners. From its first inception more than 30 years ago, modern DNA testing employing autosomal Short Tandem Repeat (STR) tests can retrieve DNA profiles from as few as four or five skin cells left behind on a touched surface. This dramatic improvement in test sensitivity has made it possible for investigators to distinguish various individuals from multiple contributor (mixture) samples.
While more “traditional” criminal investigations will always be the norm (sex assaults, homicides, high-volume crime, etc.), new applications to forensic DNA testing continue to surface. Consider the following case scenario employing modern STR kits: A motor vehicle is involved in a single-car accident – likely as a result of excessive alcohol consumption. The occupants of the car exit the vehicle before law enforcement arrive at the scene. As each individual is questioned, it becomes unclear who was operating the vehicle at the time of the accident. Ultimately, the owner of the car is charged with DUI following a positive test for alcohol. Was the owner of the car the person operating the vehicle at the time of the accident? Continue reading “Modern DNA Applications: Who was the Driver?”