Commentary on Sections Part 11 - Evidence Chapter 1 : Evidence of Bad Character Section 107: Stopping the case where evidence contaminated
383.Section 107 deals with circumstances in which bad character evidence has been admitted but it later emerges that the evidence is contaminated, that is, has been affected by an agreement with other witnesses or by hearing the views or evidence of other witnesses so that it is false or misleading (see Section 107(5)).
384.Ordinarily it is for the jury to decide whether or not to believe evidence and decide on the weight to be placed on it. In cases where a question of contamination has arisen, the current position is that the judge must draw that matter to the jury’s attention and warn them that if they are not satisfied that the evidence can be relied on as free of collusion, then they cannot rely on it against the defendant. If it becomes apparent that the evidence is so contaminated that it could not reasonably be accepted as free from collusion, the judge should go further and direct the jury not to rely on the evidence for any purpose adverse to the defence. This will continue to be the case.
385.However, there may be cases where it is not possible to expect the jury to put this evidence completely out of their mind. There are existing common law powers for the judge to withdraw a case from the jury at any time following the close of the prosecution case. Section 107 builds on these powers by conferring a duty on the judge to stop the case if the contamination is such that, considering the importance of the evidence to the case, a conviction would be unsafe. This is intended to be a high test and if the judge were to consider that a direction along the lines described above would be sufficient to deal with any potential difficulties, then the question of safety does not arise and the case should not be withdrawn.
386.Having stopped the case the judge may consider that there is still sufficient uncontaminated evidence against the defendant to merit his retrial or may consider that the prosecution case has been so weakened that the defendant should be acquitted. Section 107(1) provides for the judge to take either of these courses. If, however, an acquittal is ordered then the defendant is also to be acquitted of any other offence for which he could have been convicted, if the judge is also satisfied that the contamination would affect a conviction for that offence in the same way (Section 107(2)). Section 107(3) extends the duty to the situation where a jury is determining under the Criminal Procedure (Insanity) Act 1964 whether a person, who is deemed unfit to plead, did the act or omission charged. Section 107(4) makes it clear that the section does not affect any existing court powers in relation to ordering an acquittal or discharging a jury.