Experts discuss evidentiary value of mixed DNA profiles
Well over 50 DNA scientists and forensic statisticians of high repute from all over the world will examine the best method to establish the evidentiary value of so-called complex mixed DNA profiles. The scientists will meet to share their knowledge and to discuss this matter.
This will be the first time that so many scientists will be tackling this problem together. And this is just one of the eleven themes that will be addressed during the ninth International Conference on Forensic Inference and Statistics (ICFIS) that will be held at Leiden University from 19 August up to and including 22 August.
Mixed profiles
In the Netherlands, the police have submitted evidence containing mixed profiles to the Netherlands Forensic Institute (NFI) more and more often. This is due to the fact that the techniques to obtain information from these profiles have become increasingly more sophisticated. “This evidence may contain extremely valuable information", said Ate Kloosterman, scientific researcher at the NFI.
Far more than half the items of evidence submitted to the NFI concerns transferred biological material. These items can include, for example, a victim's article of clothing that was grasped by an offender, or evidence secured from a crowbar used by an offender. In practice, it often turns out that transferred biological material contains DNA of two or more persons. In the laboratory, the analysts obtain complex mixed DNA profiles from such mixed biological material.
The statistic interpretation of the evidentiary value of a single DNA profile is relatively simple. Where a complex mixed DNA profile is concerned, statistic interpretation is much more complicated.
Interpretation of evidence and statistics
ICFIS is an international conference bringing together statisticians, forensic scientists, and professionals from the criminal justice system. During ICFIS2014, forensic scientists will exchange knowledge about the methods used and the results achieved by these methods. The conference was held for the first time in the eighties. This is the first time that this triennial conference will be held in the Netherlands.
The four-day conference is being organised by endowed professors Charles Berger and Marjan Sjerps of the NFI. Nearly 200 experts and lawyers from 26 countries will tackle different themes on the interpretation of evidence. For example: How different is the legal and scientific approach to statistic evidence? Or: How can we quantify and combine the evidentiary value of different types of evidence?
In addition to workshops, there will also be discussions and lectures, including those given by NFI experts.