It was a nice month, with some casework, some work for the Forensic IT working group of ENFSI www.enfsi.org and developing new tools that are also used in casework such as http://prnucompare.sourceforge.net/, which were developed by our team. It includes now also wavelet methods published by Fridrich et. al. and batch processing, since these methods can be time consuming in calculation time.
It is good to see that work in literature is implemented in easy to use open source software, such that published methods in literature are available in the open source community, and it becomes easier to validate the different software approaches. We also have a database with some examples on line at http://forensic.to/prnu . Of course validation of the uniqueness of PRNU patterns with different cameras is always needed before reporting and drawing conclusions based on the results.
Sunday, April 05, 2009
In this time, after my vacation, we finally do not have much backlog, so more time to review articles, and preparing presentations and of course to make new projects.
I also went to an interesting conference in the Netherlands, about problems in forensic expertise in Amsterdam, organized by the court of Amsterdam, where also lawyers could attend. This conference also went in depth in to different aspects of forensic science, eyewitness testimonies, forensic psychiatry and how the court interprets the findings. There was also some discussion about the NAS-report , and also having a forensic entitity as meant in this report in the Netherlands. One of the examples that was given, was the Phantom of Heilbron , where 40 cases in Western Europe where linked based on DNA for no apparent reason also with a murder case. It finally appeared to be a contamination case, since the cotton swabs where contaminated by the producer of these swabs with DNA of one of the employees. It is good that this came out, since now other labs are also aware of this kind of contamination, and can look at there quality assurance system to prevent this.
Also the issue that forensic scientists can be biased based on the information they will receive around a case, and that this might influence there conclusion. Ton Broeders presented a method to prevent this, by doing blind examination in comparison cases.