Mr Webster (for the defence) at JB's 2002 CoA hearing:
vi) Whilst he accepted that the method of testing was the standard approach to blood grouping at the time, it was only applicable to "a run of the mill" case where it was known that each bloodstain was from a single individual. When there was a risk that it might be from more than one blood source, as here, Mr Hayward should have taken steps to ensure that the different group tests were carried out on the same material. This could have been achieved either by dissolving the whole flake and forming a single solution or by crushing the flake and pulverising it to ensure that all parts were completely mixed.
http://www.homepage-link.to/justice/judgements/Bamber/index.html
I don't think the tests involve slides and microscopes. As I said previously I believe the tests are based on gel electrophoresis. Same sort of tests for DNA but in JB's case it was based on blood serology of enzymes and proteins (all enzymes are proteins but not all proteins are enzymes). The test separates molecules by their size. Unlike DNA it's not statistically individualising.
https://www.youtube.com/watch?v=AkBUriMK9u8
https://en.wikipedia.org/wiki/Gel_electrophoresis
I guess there are three issues in red above: a) from a legal perspective giving the jury the benefit of allowing them to consider the possibility that the blood may have been a mix of NB's and June's. And b) from a ballistics perspective this seems so unlikely that the prosecution could and should have demolished the argument. Malcolm Fletcher said one of the shots June sustained might have been a contact shot but according to him it was "unlikely". None of the shots NB sustained were described as contact. I guess it could be argued that blood from the beating NB sustained from the silencer/rifle entered the silencer. And c) the notion SC would return the silencer to the gun cupboard having shot herself. This might have been plausible if it was found in the front of the cupboard but it was in a bag at the back.
To my mind even though John Hayward didn't follow the correct procedure I can't buy into the idea that the blood results represented a mixture of NB and June's. I think Geoffrey Rivlin cocked up big time and defence lawyers since have been trying to pick up the pieces and running with the blood results representing a mixture of NB's and June's instead. Imo GR should have gone down the fabricated evidence route in the first place. It was all there on a plate: the 'chain of custody', the fact blood serology testing is not statistically individualising and blood pattern analysis. If they knew about the fuming chamber surely this would raise further queries along with the fact the flake was able to produce significantly more results than any other exhibit.
The trial testimony was that very little blood from the beating could theoretically get inside and if it did then it would not be able to far at all. The jury was told there was too much blood and it was too deep inside to be from the beating.
Rivlin felt that his best chance was to try to get the jury to believe it possibly was a mixture and hope the jury would feel this amounted to reasonable doubt. This was a weak argument for numerous reasons but the best he could do under the circumstances. Evidence that went against this was the jury being told it was unlikely any of the wounds to June and Nevill were contact wounds thus unlikely there would be any chance of drawback. Worse still hey were told the only way for it to be a mixture and for this not to be detected would be if the blood did not intimately mix yet testing showed blood would intimately mix in a moderator. They were told AK1 is more hardy than AK2-1 and that since AK1 was detected then if June's blood had been present then AK2-1 would have been detected. He hoped the jury would overlook such and simply listen to Hayward saying a mixture was a possibility and them just believing that amounts to reasonable doubt. He hoped they were not so bright and could be taken in by this. Obviously another flaw in this is that it is not credible that in a crazy rage she would take the time to go get the moderator to attach it and use it let alone to put it away when she was done. But this was the best argument the defense could come up with because they are limited by the facts of the case.
Chain of custody is a legal issue and required for authentication. That was satisfied in this case. By discussing the chain of custody you seem to suggest they should have asserted the blood was planted by the family. They had no basis to suggest such though. As much as some hate Anne there is nothing to suggest she would be a party to such a deception. Nor is there anything to suggest the family knew Sheila suffered a contact wound that would result in drawback or knew anything about drawback period let alone would know how to plant blood inside so as to simulate drawback. Without being able to prove such knowledge as well as opportunity it is not something courts allow and not something that has much of a chance of a jury believing anyway. You need some evidence to support such happened.
In this case only the lab had the knowledge about drawback. Yet blood was found right away and there is nothing at all to suggest the lab planted anything.
You are criticizing them for not using evidence you don't have. You are counting on evidence you will get from testing that you don't yet have and for reasons previously discussed won't have. Lawyers need witnesses to present evidence. The defense in this case had zilch to try to attack the moderator evidence. The best they could think up was the rather novel idea of getting Hayward to admit there was a remote possibility it was a mixture and that being able to sway the jury. While it didn't work it was the only thing they had and better than not making any argument at all.
If defense testing of the blood revealed a preservative agent then the defense would have been able to have an expert note such and say this suggests the blood was planted not directly from a human. But they had no such evidence. Even today nothing has been found to support such.
If they didn't suggest the blood was a mixture they would have basically had no defense at all against the evidence and just have featured Jeremy insisting he is innocent.
Aside from no evidence to suggest police planted anything think about it logically. If police had known about drawback and had planted the blood and removed blood from the rifle so the lab would not find any what would the police do? They would make sure the lab tested such blood right away to come up with their conclusions. Did police press the lab to test blood right away? No Cook first fingerprinted the moderator then superglued it and took his sweet time getting it to the lab. Did the lab process it right away? No they took their sweet time as well. Is there anything to suggest police put any pressure on the lab to move faster? There is nothing the defense could have latched on to.
Officer Cook did you plant any blood? No
Officer Jones did you plan any blood? No
Ms. Howard did you plant any blood? No
Mr. Hayward did you plant any blood? No
Had the defense asked such, after they answered no what could the defense do? Nothing. How would this help matters even if the court didn't sanction them? People get their ideas about trials largely from TV and things in real life are different.