I, R & T, R. v

This is an appeal by the prosecution under section 58 of the Criminal Justice Act 2003 against the ruling by His Honour Judge Sampson sitting in the Crown Court at Kingston-upon-Hull on 3 February 2012 that the expert evidence it wished to adduce in the trial of the respondents was inadmissible. The admissibility of that evidence was the only issue before this Court.

For most of the period on the indictment, R andT (his daughter) were the only directors of I, which operated Duck Nest Farm. The company had DEFRA approval to receive and process category 2 and 3 animal by-products.

The respondents were charged with failing to process blood by heating it to the required temperature before disposing of it as fertilizer. Counts 1, 3, 4 and 15 of the indictment charged such failures.

Blood would be received by I at its plant. It would be received into vast cookers where, if the requirements of the regulations were followed, it would be cooked to at least 133 degrees centigrade for 20 minutes at a pressure of 3 bar. From the cookers the blood would go into a tank known as the green tank and from there into a tanker for distribution to farms where it would be applied as fertilizer or into a tank at Duck Nest Farm known as the lagoon. From the lagoon it would go into a tanker for distribution.

In 2008 Simon Goodwin, a senior animal health officer became involved with the respondents following a complaint from a poultry farmer in East Yorkshire. He said his flock were becoming ill because of a fertilizer being used at the nearby Meux Decoy Farm. The fertilizer consisted of blood from the I plant. There was (and is) no scientific evidence supporting the poultry farmer’s allegation that the fertiliser was the source of the flock’s illness, but the allegation led to the testing of animal by-products dealt with by I.

On 1 October 2008 Mr Goodwin took samples of the fertilizer from the residual outlet pipe on the farm storage tank at Meux Decoy. He did not think it appropriate to test the sample for bacteria salmonella, clostridium and enterobacteriacea because of the risk that any bacteria found in the blood may have arrived after processing. He therefore required a different test to determine whether or not the blood had been processed. This led him to Mr Reaney a recognised expert scientist in the use and application of counter immuno electrophoresis (“CIE”).

CIE is a test for the presence of animal proteins in the blood. If the blood had been heated to a temperature in excess of 75 degrees centigrade no proteins would be found. The presence of animal protein would then demonstrate that the blood had not been heated in accordance with the regulations to 133°C. Avian protein was found in the sample taken from Meux Decoy. This formed the basis of count 1 in the indictment.

On 4 November 2008 samples were taken from the lagoon at Duck Nest Farm which tested positive for avian protein, but negative for bacteria. This sample led to count 3. Clostridium bacteria are destroyed at 120°C.

On 21 November 2008 samples were taken from the green tank. Three samples were taken in total. Two tested positive for avian protein. This was the basis for count 4.

On 9 March 2010 samples were taken from a field pump mechanism used to distribute processed blood and this tested positive for bovine, porcine and avian proteins. This was the basis of count 15.

The prosecution sought to prove their case by relying on the evidence of Mr Scott Reaney in relation to the scientific test known as the counter immuno electrophoresis (CIE) test.

The judge accepted that Mr Reaney is a recognised scientist expert in the use and application of CIE. He also accepted Mr Reaney’s evidence that:

The judge continued:

The judge said:

He continued:

The judge then referred to the facts that did in his judgment cast doubt on the reliability of the CIE test results in question.

Dilution of the sample by processed blood thereby reducing the bacteria in the sample to below the detectable threshold.

There were no detectable bacteria in the unprocessed blood in the first place.

A chemical agent such as disinfectant has killed the bacteria in the unprocessed blood.

He concluded:

In her admirably brief submission, Miss Robinson submitted that the judge had confused the question of admissibility of expert evidence with the question of the weight to be given to that evidence.

In his similarly concise submissions, Mr Thomas QC contended that the judge was right to reject the admissibility of the prosecution expert evidence for the reasons he gave.

Mr Reaney, the prosecution expert, was acknowledged as an expert in his field. Indeed, when Mr Woodgate, the defence expert, who has no experience of CIE testing, sought an expert on the use of CIE, Mr Reaney was recommended. The CIE test is accepted by the scientific community as a reliable test to distinguish between, for example, avian and bovine protein. In this case, it was used for a less demanding purpose, simply to test for animal proteins that not been denatured. There is no evidence that the test would show positive for denatured animal protein. The test was used in this case for a new purpose, but that does not of itself render the test unreliable or its results inadmissible.

In the present case, there are two findings to which the judge referred that may indicate that the results of the CIE tests are inconclusive or unreliable. The finding to which the judge principally addressed was the absence of the specified bacteria in samples tested positive for animal protein. Since the required heat treatment would eliminate these bacteria, as well as denature animal proteins, one would expect bacteria, as well as animal proteins, to be found in any untreated sample. It was therefore necessary to consider whether the finding that samples were bacteria-free indicated that, contrary to the prosecution case, they had been the subject of the required heat treatment, and that the CIE test results were unreliable.

However, if there is a soundly based scientific explanation for the two findings, of no bacteria but of animal proteins, neither finding casts doubt on the reliability of the other or of the inferences to be drawn from them.

The prosecution suggested three explanations, which the judge numbered. We can set aside the second in the judge’s list, that there were no detectable bacteria in the unprocessed blood, which Mr Reaney conceded to be a fanciful explanation.

However, the other two are explanations which do not indicate inconsistency with the reliability of CIE testing. They were advanced by Mr Reaney. The judge did not find that they were scientifically unsound. That those explanations are unproven does not necessarily indicate that the CIE tests were unreliable. If in fact the relative volume of unprocessed to processed blood was so small that the bacteria in the sample was at an undetectable level, whereas, by reason of its sensitivity, unprocessed protein at the same level of dilution is detected by CIE, there is no inconsistency.

However, the prosecution have not adduced any evidence to support what is little more than conjecture on the part of Mr Reaney. They have not put in evidence as to the sensitivity of the bacteriological testing. If that testing is as sensitive as the CIE test, this explanation would have been shown to be inapplicable and irrelevant.

The other explanation put forward is that a bactericide had been added to the blood from which the samples were taken. Again, there is no evidence to support this suggestion. It appears that the samples were ph neutral, so that if any bactericide was added, it was either ph neutral or at such a low concentration in the bulk from which the samples were taken as not detectably to affect the ph level. Whether there is a ph neutral bactericide, and if so whether it would have been practically or economically available to the respondents, are not in evidence. Mr Woodgate has put forward good reasons for rejecting this hypothesis, but the judge made no finding about them.

The judge also referred to the oddity that only avian protein was found in the green tank and in the lagoon, whereas on average the blood and other matter coming in to the respondents’ plant is 80 per cent avian and 20 per cent mammalian. However, if an untreated delivery comprised only avian blood (having originated, for example, from a chicken farm) this would not be an oddity, and would not indicate any unreliability of the CIE test results.

Against all this, we have no suggestion from the respondents as to how animal protein that had not been denatured could have found its way into the treated blood. As the judge noted, Mr Woodgate was unable to pose a scenario in which the CIE test would produce a false positive result.

In our judgment, once the judge concluded, as he did, that “the CIE test is a well-recognised and reliable test for establishing whether or not animal protein is or is not present in blood”, the CIE test results were admissible on the basis of Mr Reaney’s expert evidence. The fact that the test was used for a new purpose, or in a new context, did not of itself render the test unproven. If the test had been applied to clearly untreated blood, to ascertain whether or not it was avian, it would have been applied for a previously established purpose. Its use to detect avian protein is not very different. Furthermore, it is common ground that heating blood to a sufficient temperature denatures animal protein so that it is not detected by the CIE test. So far, we agree with the judge.

However, when the judge proceeded further, to lay down as the test to be applied: are “there … factors over and above the vague and fanciful that cast doubt on the reliability of the CIE test in the context of/on the special facts of this case?” the judge confused the question of admissibility with the question whether, if admitted, the expert evidence was such that on its basis a jury could properly convict I. (For present purposes, we leave out of account R and T, since the prosecution case against them involves facts additional to those that must be proved against the company.) The defence had pointed to facts (the lack of bacteria) which might be inconsistent with the reliability of the CIE tests. Against this, Mr Reaney had put forward possible explanations for those facts. If his explanations were found to be improbable, the conclusion might well be that the prosecution had not proved, or could not prove, its case. However, that decision would not be one on admissibility, but whether on the particular facts the prosecution had proved its case.

In our judgment, therefore, this appeal should be allowed. We propose to order that the proceedings for the offences that are the subject of the indictment be resumed in the Crown Court. It will be for the trial judge to rule on the basis of the evidence then before him on any application on the part of the respondents that may be made in the light of this judgment.