“In a conviction case depending on the reception of fresh evidence, the Commission must ask itself a double question: do we consider that if the reference is made there is a real possibility that the Court of Appeal will receive the fresh evidence? If so, do we consider that there is a real possibility that the Court of Appeal will not uphold the conviction?”
“Mr McCafferty told you that if cartridges are fired in a gun, there is not only a coating left inside the bore of the barrel but also smoke tends to exude from the front and from the back when the rounds are removed, if they are. That is obvious. What perhaps is not so obvious is the fact, as he went on to describe, that the outer part of the gun gets contaminated by the powder residue and in the present case, when he examined the gun if he ever did, there was such fouling in the barrels, and he took samples from the barrels, and also there was such fouling on the outside, because you may recollect he took swabs from the outer surfaces of the gun and those surfaces were in fact contaminated. He explained to you, you remember, the main constituent of such contamination. He said there was lead - lead salts which mainly come from the primer - and the technical scientific constituent, he said, was lead azide. He went on to say that hands can be fouled by these substances on the outside of the gun and also, if and when you take the cartridges out, you can get powder transferred also to your hands. It is with those matters in mind that you will recollect a number of items of clothing of the defendant were taken from him and from his home and were examined in order to discover if there were any traces of this lead residue. The items which proved to be of interest, to use a negative term, were, you recollect, the grey suit, described by, I think, Mr Lyne as the blue suit, Exhibit 46, but it is the same suit, the three-piece suit; Exhibit 47, the tan trousers; 48, the mustard coloured cardigan; 49, the two-coloured cardigan, blue and brown, and 35, the donkey jacket, all admittedly the defendant's clothes. He tested all those clothes chemically for the presence of lead deposits, and on Exhibit 46 - and on this aspect of the case there was little if any difference between the two experts, Mr McCafferty on the one hand and Mr Lyne on the other - on Exhibit 46, the suit, each of them found a positive reaction for lead over the front of the waistcoat and also on the bottom part of the jacket on the right-hand side, running down - you remember he indicated - roughly from the lower level of the point of the lapel to the bottom of the jacket. That suit was apparently not a working suit. ‘A walking out suit’, I suppose, would be the best expression to describe what the two scientific gentlemen told you, the importance of that being, of course, that the defendant, who, as we know, is a painter and decorator, would come into contact with lead based paints and if he did and if they left a residue, his clothing would of course give a positive reaction for lead. That is the grey or blue-grey suit. Exhibit 47, working type trousers. You may think you can disregard those. There was positive reaction but only at points where they were obviously paint-stained and you may think it would be fair to disregard those altogether. Exhibit 48 is the mustard cardigan. That was also a working type garment. There were a number of stains and there was a positive reaction for lead from some of the stains but not from the unstained areas and again you may think that was probably due to working stains rather than any possibility of deposits of lead from extraneous sources. The other cardigan, the blue and brown cardigan, was apparently fairly clear of staining. There was slight soiling as opposed to staining and a positive reaction was obtained, mainly from the areas of the slight soiling. Then, finally, the brown donkey jacket or the short camel-hair coat. That was clear of staining, but there was a positive reaction for lead deposits from the front and the back but it was clear on the inside of the lining. As I say, Mr Lyne was in substantial agreement with those findings. He, you will recollect, went on to say that you can get clothing contaminated from ordinary environmental reasons. He mentioned the petrol fumes from petrol which contains lead. He said with regard to the three-piece suit, in his evidence-in-chief, this: ‘The lead on the three-piece suit would be consistent with entering an environment in which there was lead with the car coat open at the front which would expose the suit to contamination.’ Then he went on to deal with Exhibit 40, which were the trousers which perhaps you need not bother about, but what he went on to say in cross-examination was this: ‘So far as the suit is concerned, Exhibit 46, the ordinary petrol fumes in a street would not produce a positive reaction’, and you will remember, no doubt, that he distinguished between that type of general contamination and a specific type of contamination which would happen, for instance, if you placed your leg with the trousers on it immediately behind an exhaust pipe. The other possibility which was mooted as a reason for lead contamination was the sanding off of lead-based paint, which might produce a powder containing lead which, in its turn, might contaminate clothing. Against that, you have to balance the fact that, in the view of these two gentlemen, the blue-grey suit was not a work suit. There it is. There is no possible explanation forthcoming that I have been able to extract from the evidence apart from the environmental possibility and also the sanding off of paint; that is to say, with regard to the best clothes. With regard to the working clothes, I have perhaps dealt with that already and there we can leave the scientific evidence.”
“While we endorse [prosecuting counsel’s] broad proposition that the change of approach to evidence of gunshot residue does not necessarily determine the appeal, had the present scientific concerns explained by [the expert witness] been available to the judge, we have no doubt that his directions would have been couched in terms of much greater circumspection and caution. The particles of gunshot residue may well be consistent with the appellant’s participation in the murder but, at the very least, the extent (if it got that far) to which they could provide positive corroboration would now have required much more detailed analysis of the science and the evidence.”