Samenvatting

It is common knowledge that when driving a vehicle, people leave traces of DNA behind. However, in the context of vehicle crimes, it is helpful for the police and investigative personnel to know the vehicle locations in which a perpetrator most likely left DNA during the incident. By specifying the most informative locations to sample for incidental driver DNA, time and resources can be saved in criminal investigations. This study extends previous knowledge by focusing on the prevalence and persistence of incidental driver DNA in vehicles. Furthermore, the current study investigates the prevalence of DNA on vehicle locations from the regular driver and the close associates of the regular driver and incidental driver. The same experiment was conducted by two laboratories, allowing for inter-laboratory comparisons. The results confirm that DNA from the last driver of the vehicle is most likely recovered from high contact areas for operation of the vehicle like the steering wheel and gear shift. Most sampled sites within the vehicle contain DNA from the regular driver of that vehicle. DNA from an incidental driver is most likely to persist, even after resumed use of the vehicle by the regular driver, on locations with a higher retention capacity for biological materials like the car seats and seat belts. Overall, this paper highlights the patterns of DNA transfer, persistence and recovery that occur depending on an individual's relationship to a vehicle. This information can be used by crime scene investigators for targeting the most relevant sampling locations given different scenarios of vehicle use.