Have you ever wondered why detectives don’t use DNA to construct an image of what the suspect may look like, rather than just comparing DNA to a crime database? Well Christopher Phillips, a forensic geneticist at the University of Santiago de Compostela in Galicia, Spain, certainly has and for very good reason.
The idea certainly makes sense; by constructing a virtual image of a suspect it would be possible to compare the features of the person to a much larger array of people than just those who have committed a crime. For ex ample, in 2007 a judge ordered that DNA from a bombing in Spain be determined to be European or North African. The reason for this is that two groups were suspected of being behind the attacks: The Basque separatist group ETA and Islamic Militants. Members of the ETA would most likely be of European descent, whereas Islamic militants would almost certainly be of North African descent. By making the distinction of which ancestry the DNA from the bombing site was linked to detectives were able to hone in their search into more refined areas.
The current method of determining a suspect’s ancestry is through use of Y-chromosome and mitochondrial DNA; however this method becomes inaccurate when interbreeding between two different races occurs. However, Phillips’ team at the University of Santiago de Compostela have managed to discern that the DNA collected from a toothbrush of the bombing site in Spain was of North African ancestry by genotyping 34 single DNA letter differences in the chromosomes from the unidentified samples still connected to the bombing. This result was later confirmed when the DNA was later linked to Daoud Ouhnane, a suspect in the case and is still at large. Interestingly the findings were in conflict with that obtained from Y-chromosome and mitochondrial sequences.
Despite the excellent results, it is unlikely that this method of genetic profiling will become widely used for quite some time. There are fears that genetic profiling may be construed as prejudiced to certain ethnic groups. Until such fears can be abated in the general public genetic profiling will remain in the world of high profile cases such as the Madrid bombings. It is, however, an exciting prospect that we can hope to look forward to.
Posted by Alistair Lavers - 42048468
Original Article:
Newscientist Magazine, 'DNA mugshots' narrow search for Madrid bombers, http://www.newscientist.com/article/dn17630-dna-mugshots-narrow-search-for-madrid-bombers.html, 18th August 2009