DNA results
05 août 2008The parents are less and less credible?
Since the case file has been accessible to the press, all the media are commenting on it. All the Portuguese newspapers are disclosing worrying details, placing in doubt the assertions of the parents. In fact, many details remain difficult to explain. Many details, facts and witness statements, contradict the assertions and statements of the parents and their friends. Of course, the details revealed in the press are not going to be favourable to the McCann family. And for the reason that the investigators built up an opinion of them and that opinion flows through the pages. Be careful, however, not to put words into my mouth: I am not claiming that the PJ directed the investigation according to their beliefs. Quite the opposite! The investigation was conducted as it should be. It is the contradictions, the gross inconsistencies, the lack of cooperation, the parents' inappropriate reactions, which naturally led the investigators to suspect the parents. You know all the worrying details we are talking about:
- Kate going back to her friends, shouting: "They have taken Madeleine," but leaving her children in the apartment where an abduction has just been committed.
- The friends who set about looking for her, but who do not go and look in their own apartments to see if she is there or their children are still there.
- The bedroom perfectly tidy and Madeleine's bed undisturbed. (Thanks to the kidnapper for having remade the bed or else Madeleine was not in her bed at the time she disappeared.)
- The fact that British diplomats were advised and that they put pressure on the police investigation. (Kate admitted in a British newspaper, a few days ago, having telephoned the British Prime Minister to ask him to put pressure on the investigation so that, "progress is made."
- The contradictory statements about the forced door (which wasn't), the dilapidated and forced shutters. (which were not that either).
- The witnesses who didn't see the same things as the parents and their friends while being in the same places at the same time. (299 witnesses were questioned).
- The inconsistencies in the statements by the group of friends.
- The lack of cooperation from the group.
- The refusal to participate in a reconstruction (Yet crucial in finding out what happened to Madeleine - isn't that the only objective?)
- The blood found in the bedroom.
- The cadaver odour detected.
- Etc
The action of the British dogs, specially trained to detect the odour of corpses and human blood was decisive in Gerry and Kate's being suspected. Given the coincidences faced with the action of the two dogs, who indicated the same places as well as the same objects, the authorities were obliged to admit the possible involvement of the parents in their daughter's disappearance and to designate them, "arguidos," in order to confront them with elements which could lead them to an indictment. The inspectors explain that the dogs gave signs of detecting the odours of human corpse and blood in the places and on the objects that follow:
In the apartment from which Madeleine disappeared (In the bedroom and in the lounge)
In the kichen garden.
In the vehicle rented by the parents 24 days after Maddie's disappearance.
On two items of Kate's clothing.
On Maddie's soft toy which Kate did not put down in the days following the disappearance.
In the apartment of friends of the McCanns, in the village of Praia da Luz and in vehicles used by Robert Murat - the first accused of being suspicious - nothing was detected by the dogs.
On the other hand, articles will focus on the DNA analyses...
The DNA results.
The media war has begun. The British newspapers do not speak the same language as the Portuguese newspapers. Thus, Clarence Mitchell, the parents' spokesperson, states in the British press: "The DNA results were never 100% compatible with Madeleine's DNA. A note of caution had been expressed at the outset. The police were wrong to pursue this line of investigation. The Portuguese judicial system has admitted having no evidence! I can confirm that the PJ stated to Gerry that Madeleine's DNA had been found in the two apartments and in the vehicle, while it is now clear that that is not what the first report from FSS said. You must ask yourself what the police were trying to do in inventing evidence which they don't have and which they cannot have. In these circumstances, it could be asked what is their motivation."
We are going to flatten Mr Mitchell's statements somewhat. From the point of view of a police officer, it happens that the police tell suspects that they hold evidence, which they don't in reality have, in order to crack a suspect; this should not be done any old way. Indeed, it is difficult to tell a suspect, for example, that his fingerprints were found at a crime scene while the suspect knows that he appropriately wore goves throughout his offence and that as a result the police are talking rubbish! You must be quite serious. Putting forward evidence which you don't have must remain plausible, knowing that if the suspect is indeed the guilty party, the police will lose face if they invent evidence that the suspect knows to be false!!
On the other hand, Clarence Mitchell's interpretation of the DNA results invite circumspection. To help us with our thinking, our association called upon an expert on the subject. She is Madame S. Adamis, Legal Expert at the Centre for Human Genetics at the Catholic University of Louvain. (GNEX - UCL)
Association Enfants Kidnappés: Do you know about the LCN technique and is it commonly used?
S.Adamis: LCN (Low Copy Number) is a technique developed by the laboratories of the English Forensic Science Services to analyse samples containing a very small number of molecules of DNA. The basic principle is to increase the number of PCR cycles to increase sensitivity. [Gill, 2000; Whitaker, 2001] This technique has two major drawbacks:
1) It produces unbalanced profiles for one or more markers, with possible disappearance of an allele due to the stochastic* effect.
(*Involving chance or probability)
2) It leads to the detection of one or more alleles in negative controls of unknown origin.
The first drawback leads to obtaining an incomplete profile, partially wrong and not reproducible. This low reliability goes against principles of quality advocated notably by standard ISO 17025 in force in our country.
The second requires necessarily working in special conditions to avoid contamination inherent in the environment and particularly from human DNA present in the dust in the atmosphere or on the surfaces of objects. Given the limitations of this technique, the conclusions produced could easily be attacked or invalidated during a trial. This technique is not routinely used in laboratories for genetic identification in Belgium.
AEK: If in a DNA analysis, 15 out of 19 markers belong to person, "x", can we conclude that it is indeed from that person?
S.A.: If the profile is complete and of quality, and the analysed markers are informative, then without doubt! The result is discriminating. This result is very very reliable. The error is in the region of 1 in a billion! It is almost impossible for it to be otherwise. For a convincing DNA profile, there must be a minimum of 7 base markers. In the case which you present, 15 markers out of 19 does not leave any hanging doubt. This result is completely reliable and usable in court. The error rate of one in a billion is so unlikely that the results are accepted by magistrates without lawyers being able to place them in doubt.
We are going to digress here. We understand even better the attitude of the PJ. Indeed, faced with the inconsistencies we are talking about above, the police officers have doubts. Then the dogs detect traces of blood and cadaver odour. The doubts transform into beliefs. But something is missing. All these elements are not sufficient to face charges in a court. Confirmation is lacking. Scientific confirmation. That confirmation arrives with the first report of analyses which states that 15 out of 19 DNA markers belong to Madeleine. That's all the police need. The evidence is there. Obvious. The first report of the analyses proves the parents' guilt in the eyes of the investigators. This report would be considered as irrefutable proof by, I believe, all the police. From then on the parents were placed, logically, under the specific status of, "arguidos." Of course, an error rate of 1 in a billion is not a 100% profile, in that Clarence Mitchell is right. Then, afterwards, comes a thunderbolt.* A second report from FSS arrives and totally contradicts the first. Also ruining the evidence the police thought they had. According to this report, the harvested samples would have been contaminated, making them very unreliable in the end. Several DNAs would have been mixed, creating the DNA of anyone!
* I took liberties there with the interpretation because that was the best phrase that came to me in the context!
EAK: If we harvest the DNA of three different people, can we recreate the DNA of anyone?
S.A.: If the harvested DNA is mixed with the DNA of three individuals in a balanced way, then effectively we could find the DNA profile of anyone. Mine just like yours. But the mixture must be perfectly balanced, otherwise the rate of reliability becomes very low, going from 1 in a billion to 1 in a thousand or 1 in a 100. It is no longer a question of considering this result as discriminating.
Ok, what happened? LCN unreliable? The samples contaminated during the second analysis but not in the first? The first analysis botched by FSS? There would be a good way of finding out. When two experts contradict each other, a third analysis is carried out in an independent lab. But, alas, following an incident that remains unexplained, the only existing DNA samples were, unforunately, lost or destroyed by the laboratory, which renders impossible a third analysis!
