Forensic traces of individual variation

We all have a different shedder status

When we touch an object, or even move about in a room, people leave behind traces, including trace DNA. DNA in particular is of great importance for forensic investigations, as it can help track down criminals. To complicate matters, however, the extent to which people deposit trace DNA, also known as their shedder status, differs from one person to the next.

Impact on science

With his research, Meeuwissen wishes to contribute to a broader understanding of this phenomenon, and while it has been studied for some time already, the exact mechanism and underlying causes are not yet clear.

More knowledge on this topic would open up many new avenues. We could develop a shedder test, for instance, for subjects participating in studies on forensic trace dynamics.

Jaimy Meeuwissen

Project manager and researcher

Impact on practice

The shedder status of individuals and its significance for the credibility of evidence have also been brought up in the legal realm, with the Nicky Verstappen case being a particularly striking example. In this case, the defence argued that the accused was a "DNA bomb" when he touched the victim, due to temperature, physical activity and emotions. Whether and how such factors truly affect shedder status is investigated within this project.

Methodology

In this project, Meeuwissen combines theoretical literature research on the fundamentals of the phenomenon with practical experiments. An initial experimental study focuses on DNA traces under fingernails, which can be very important in violent cases and sex offences. The study will aim to ascertain the extent to which different individuals shed DNA more or easily, how shedder status affects foreign DNA found under fingernails, and what this means for the interpretation of such traces in practice.

Education

Students from forensic degree programmes taught at AUAS and the University of Amsterdam will be involved in the project, helping to make sense of this complex issue in internships and graduation projects. In addition, the knowledge gained will be incorporated into the curriculum of the relevant degree programmes.

Partners

For this project, Meeuwissen has been seconded from the Judiciary, where he assists judges as a forensic consultant. In experiments, he collaborates with the Netherlands Forensic Institute and the University of Amsterdam, among others.

Contact

For more information, please contact Jaimy Meeuwissen.