Based on a series of criminal cases in the UK, where Therese Graversen was involved as an expert witness, she explains why it can be extremely difficult to evaluate DNA evidence and what role a statistician has in the legal system.
DNA is generally perceived as highly conclusive evidence, but in practice it can be surprisingly hard to determine the origins of a DNA sample. One of the challenges arise from samples of DNA that consist of DNA from several people. Just as there are many ways of adding two numbers to sum to 10, there are often many ways of mixing DNA that would lead to the same composition of the mixed sample. So, if the only evidence from the crime scene is a mixed sample of DNA, it is not at all straightforward to determine who were present.
In her talk, Therese will illustrate some of the issues by a puzzle where the individual peoples’ DNA make up the pieces. Can you find a way to match people to the DNA sample from the crime scene?
16:30 Talk begins
17:15 Small Break
18:30 End of Event