Dutch screen DNA of 8,000 men to solve 13-year-old murder
What may be the largest mass DNA screening ever to be conducted has just started in the Netherlands. More than 8,000 local men are being invited to contribute their DNA in an attempt to find relatives of whoever raped and murdered 16-year-old Marianne Vaatstra in 1999. Processing such large numbers of samples has now become easier and quicker, thanks to a new software tool and automated technology developed by the Netherlands Forensic Institute (NFI).
The strategy
Although a man’s DNA was found at the scene of the crime, no match was found in the national DNA database of offenders so it was impossible to establish his identity. However, investigators believe he may have been a local. So following a recent change in the law to allow mass DNA screening under certain conditions, they decided to screen the DNA of all males who, in 1999, were aged between 16 and 60 and lived nearby. The aim is to find people who share some Y-chromosomal DNA with the offender and may therefore be related to him. It is hoped that this information will then help the police identify the killer himself. The samples will only be used for this investigation and will be destroyed afterwards.
Biggest operation of its kind?
This procedure (known as ‘familial DNA searching’) is being carried out by the Netherlands Forensic Institute (NFI), who believe that the operation may be the biggest operation of its kind done anywhere so far.
Advanced technology
To speed up the process, the NFI is using a software tool it has co-developed with Radboud University Nijmegen. This uses state-of-the-art mathematical probabilistic methods to determine quickly and accurately not only direct matches but also the sort of ‘pedigree’ matches against partial and full family trees required in the Vaatstra case. The tool (called Bonaparte) has already proved its value, having been used successfully to rapidly identify the more than 100 victims of the Tripoli air crash in 2008. The NFI expects to complete the analysis of the Vaatstra profiles in well under six months. Since the process is almost completely automated, it will not hold up normal work.