The sound moderator, Sheila Caffell and the DNA found therein

[John]

The FSS have now disbanded so it is useful to retain this information proovided by them and retained under cache as Bambers advocates continue to state that Sheila's DNA was not found in the sound moderator.

The important bit I have highlighted in red!


Jeremy Bamber

Forensic Science Service (FSS) scientists gave evidence for both prosecution and defence in the failed Jeremy Bamber appeal, reinforcing its reputation for impartiality and as an independent provider of forensic expertise.

After a high profile trial in 1986, Bamber was convicted of the shooting of his adoptive parents, June and Neville Bamber, his adopted sister, Sheila Caffell and her six-year-old twins. Bamber has always protested his innocence claiming that Sheila was responsible for their deaths before committing suicide.

The case was unusual in that it was common ground that only two explanations for the five killings were possible. The first was the prosecution case that Jeremy Bamber entered the Essex farmhouse owned by his mother and father at night and shot the five members of his family with a legally-held rifle. At the heart of the original prosecution case was evidence that Sheila’s blood was in the sound moderator, or silencer, of the murder weapon. If so, she could not have shot herself then put it in a cupboard downstairs.

The second, the defence case, was that Sheila, who had a history of psychiatric illness, had shot the four members of her family with the rifle and then committed suicide. In the initial stages the police thought it likely that the second explanation was correct. Some officers, however, thought that some of the findings were inconsistent with this explanation and members of the Bambers’ extended family did not believe that it was consistent with their knowledge of Sheila.

Bamber’s case was referred back to the Court of Appeal in 1998 by the Criminal Cases Review Commission, which investigates possible miscarriages of justice. The appeal was based on 15 grounds – the majority relating to documentation and other evidence which it was suggested was not made available to the defence before or at trial, some serious allegations were also made against the police to suggest there was evidence of a conspiracy to pervert the course of justice by deliberately concealing evidence helpful to Bamber’s case. However, the appeal was centred on new DNA evidence and an attack on the original blood testing evidence. This led to further forensic work being carried out by a number of FSS scientists.

Bamber’s QC, Michael Turner, claimed the original defence team had been misled by a former FSS scientist into believing that the whole of a blood flake recovered from the silencer had been mixed in solution before being subjected to blood grouping tests. It had, but had been broken first into four pieces before being dissolved in water.

A forensic scientist gave evidence for Bamber’s team claiming that dissolving the whole flake might have prevented the detection of a mixture of blood types which could have shown that the original flake was a mixture of blood from June and Neville Bamber.

Bamber’s case was that fresh DNA evidence from the silencer backed this theory after a DNA profile was obtained from the baffle plates inside the silencer. There were 17 of these cup-shaped plates which, when put together, help to absorb the sound when a gun is fired.

Although the baffle plates had been originally examined by scientists in 2000, it was agreed that they’d wait for a year until the latest supersensitive tests - DNA Low Copy Number (DNA LCN) - could be used.

When these baffle plates were swabbed a strong female profile was obtained along with minor male contributions. The court heard that the profile could not have come from Sheila Caffell and further attempts to identify the source were attempted.

The victims’ reference samples had been destroyed by Essex Police 10 years after the trial, so there were no profiles available for direct comparison purposes.

The situation was further complicated because the gun and silencer had been put back together and dissembled making it possible for trace evidence to be transferred from one area to another.

Statistical tests on a DNA profile from June’s sister were carried out to give an indication of whether this unidentified female profile could be from June. The Appeal Court was told that, based on the profile of her sister, there was strong evidence to support the assertion that this female profile was from June. However, it wasn’t possible to find out whether this DNA originated from blood, or other cellular material, or say how it got there or when.

The court then heard how several other areas inside the silencer had also been subjected to DNA LCN tests and complex mixtures obtained. Senior forensic scientists for both the prosecution and the defence said they couldn’t exclude Sheila Caffell from being a contributor to the mixtures. However, because of the complexity of the mixed profiles it had not been possible to statistically evaluate the significance of these findings.

One of them went on to explain that the FSS had carried out experiments involving computer simulation to determine the average number of bands that might be shared by chance in a three-person mixture. These experiments indicated that as many as 13 could be shared by chance alone. However, in this case, all but three of the 20 bands from Sheila’s profile were represented in the mixture, providing positive evidence to support the opinion that DNA from Sheila was present. However, as it couldn’t be determined whether this DNA came from blood, the evidence was effectively neutral and therefore not helpful to either side.

The original firearms work was carried out by an FSS firearms expert, who used the available information to try and determine in which order the 27 shots were fired. This was not presented to the court because counsel recognised there was an element of speculation. Also some firing tests to determine the likelihood of finding discharge residues on Sheila Caffell, performed originally, were repeated.

The three judges said they had “no doubt” the verdicts were safe and rejected all 15 points on which Bamber had made his case for freedom.


http://webcache.googleusercontent.com/search?q=cache:S_0l7k__nukJ:www.forensic.gov.uk/html/media/case-studies/f-31.html+http://www.forensic.gov.uk/html/media/case-studies/f-31.html&cd=1&hl=en&ct=clnk&gl=uk&client=firefox-a

[John]

It should be noted that it cannot be stated where the DNA found in the sound moderator and attributed to Sheila Caffell in these most latest tests came from.  It may have been blood but that cannot be confirmed as so little material remained in the sound moderator.

We must remember however that forensic scientist John Hayward conducted the original tests on the sound moderator and concluded that the blood found within the baffles belonged to the same blood group as Sheila Caffell.

[Weety]

Yes, it is the blood evidence that  the defence have to get past, and so far I've seen no credible explanation for that.

[John]

Yes, it is the blood evidence that  the defence have to get past, and so far I've seen no credible explanation for that.

That's not all of it by any means.  I have come across an on-line article by an independent forensic science consultant Mark Webster who was involved in testing the sound moderator for blood and DNA from 1993 until 2002.

In a nutshell he explains that the blood found in the sound moderator could not have come from rabbits or any other animal of fish for that matter!  It was human blood Group A.  It was thus compatible with Sheila, June and Jeremy.

He writes...

The Bamber Case

An "official website for Jeremy Bamber" has suggested that animal blood may have been confused with human blood:

"Human blood is made up of a number of different constituents including red and white blood cells, a number of different enzymes and plasma. Forensic science uses some of these enzymes to differentiate blood samples from coming from one person rather than another.

One of these is the AK enzyme and this became important in this case. This enzyme was used to say that the blood flake discovered inside the sound moderator came from Sheila and no one else. Humans have two types of the AK enzyme, AK1 enzyme and AK2-1. The blood flake was analyzed and found to contain the AK1 enzyme therefore it came from someone with blood group A.

What the court was not told was that the AK-1 enzyme that is found in human blood is genetically identical to the AK-1 enzyme found in the blood of pigs, cattle, rabbits, chickens and the fish carp."

Rabbit AK1 is quite similar to human AK1, but it is not identical. About 5% of the structure differs between the two species. I cannot exclude the possibility that rabbit or some other animal AK1 could be mistaken for one of the human AK1 types using starch gel electrophoresis, but I think this is extremely unlikely. It should also be noted that the blood flake gave a positive result in a test for human proteins and other enzyme typing tests gave typically human results.

The ABO blood grouping system - familiar from blood transfusions - splits most of the population into the blood groups A, B, O and AB. The ABO system was also used to characterise blood in the sound moderator. The ABO blood groups reflect the structure of antigens attached to red blood cell membranes and antibodies in the blood. ABO antigens and antibodies are unrelated to the AK enzymes. The statement "The blood flake was analyzed and found to contain the AK1 enzyme therefore it came from someone with blood group A." is gibberish. A person's AK type does not predict that person's ABO group.





Read full article

[Weety]

Interesting - where did you find it?

[John]

Interesting - where did you find it?

Sorry Weety, it is taking longer than I thought to decipher it. I will post the link just now and edit the text shortly.

http://www.forensic-science.co.uk/index.html

[Weety]

Thanks, I've found it. There's quite a lot to take in, and I think to understand it properly in context I'll have to go back and read the 2002 appeal decision again.

[John]

Good luck Weety, I think he feels he is being wrongly blamed for crushing Bamber's last appeal in 2002.  The bottom line seems to be that blood group A was found in the sound moderator and that it is human group A which is the same as June, Jeremy and Sheila.

The DNA returned 17 similar markers with Sheila Caffell and it is accepted that up to 13 could be coincidental rendering it highly likely that the DNA found deep within the sound moderator did come from Sheila Caffell.

I look forward to your own appraisal.

[Angelo222]

Good luck Weety, I think he feels he is being wrongly blamed for crushing Bamber's last appeal in 2002.  The bottom line seems to be that blood group A was found in the sound moderator and that it is human group A which is the same as June, Jeremy and Sheila.

The DNA returned 17 similar markers with Sheila Caffell and it is accepted that up to 13 could be coincidental rendering it highly likely that the DNA found deep within the sound moderator did come from Sheila Caffell.

I look forward to your own appraisal.

You been having secret liaisons and ice cream get togethers with the family John?  Nice work on the blood and DNA, I must admit I cannot get my head round all that stuff though.  Keep it up. 

[Weety]

So what he saying is:

AK enzymes have nothing to do with blood groups and so the Bamber statement that the presence of AK1 meant that the blood was group A is gibberish.

Rabbit AK is detectably different from human AK, and he'd be surprised if a scientist would make that mistake, so the assertion that rabbit blood could have provided the AK1 enzyme said to be from Sheila is extremely unlikely.

One of the reasons the evidence that Sheila's DNA* was in the silencer was rejected by the court of appeal was because no one could give a statistical evaluation of the likelihood that a match of 17 bands out of 20 bands of DNA tested in both samples meant that the DNA came from a closely related person. There is now a statistical method for calculating those chances.

He criticises the CCRC for underestimating the possiblity of contamination being the source of Sheila's DNA in the silencer and also, it appears, for not recognising the significant fact that no blood was detected in tests immediately prior to the DNA tests being undertaken (because it had been swabbed out for blood grouping tests).

He appears to be saying that he just did his job, and the CCRC ended up scoring an own goal for Bamber.

* For those less familiar with the sequence of the DNA testing, at the time the CCRC referred the case for appeal the test results had concluded that DNA found in the silencer did NOT match Sheila's. Further tests were undertaken in the time between referral and appeal and DNA matching 17 out of 20 bands for Sheila's natural mother was found.