The approach to contested non-conviction bad character evidence has changed in the wake of the Supreme Court’s judgment in the case of R v Mitchell  UKSC 55.
The Crown Court and Court of Appeal
Angelina Mitchell was accused of murder. Her account at trial was that she stabbed the deceased in self-defence. She also said she had been provoked and had no intention to kill or cause really serious harm. The prosecution alleged that she had threatened or attacked people with knives on seven occasions before she stabbed the deceased and that this demonstrated propensity. She had no convictions for such behaviour. In her live evidence Ms Mitchell denied any wrongdoing in respect of all seven historic incidents. The trial judge allowed evidence about all of the incidents to go before the jury.
Ms Mitchell was found guilty of murder. She successfully appealed her conviction on the single ground that the judge failed to direct the jury properly on both the purpose of the bad character evidence and on the standard of proof to which the jury had to be satisfied before any member of the jury could take the evidence into account.
In overturning the conviction, the Court of Appeal examined the existing case law on directing juries in cases involving non-conviction contested bad character evidence. The Court identified the established approach as follows: where non-conviction evidence is relied on to establish propensity, and that evidence is disputed, the jury must be directed not to rely on it unless they are sure of its truth.
The Court endorsed the rulings in R v Ngyuen  EWCA Crim 585 and R v O’Dowd  EWCA Crim 905. In Ngyuen the Crown alleged one previous incident of violence and the Court of Appeal ruled it was necessary for the jury to be sure this incident took place before embarking on a consideration of whether it showed propensity. In O’Dowd the Court of Appeal found that three allegations of disputed bad character ought to be scrutinised as carefully as the allegation on the indictment before the jury could move on to consider whether the previous incidents showed propensity.
The Supreme Court
The question certified by the Court of Appeal and considered by the Supreme Court was: “Is it necessary for the prosecution relying on non-conviction bad character evidence on the issue of propensity to prove the allegations beyond a reasonable doubt before the jury can take them into account in determining whether the defendant is guilty or not?”
The Supreme Court endeavoured to address the issue in these terms: Should the jury be directed that they have to be satisfied beyond reasonable doubt of the veracity and accuracy of the individual facts which, it is claimed, provide evidence of misconduct on the part of the defendant? Alternatively, is the real issue not this: what requires to be proved is that the defendant did have a propensity? Or must both issues be addressed?
The Court recognised that the Criminal Justice Act 2003 offers comprehensive guidance on the issue of admissibility of disputed bad character evidence, but is silent on how that evidence ought to be assessed and treated by the jury once it is admitted. The common law predating the Act gave no clear statement on the issue.
The Court embarked on a fresh consideration of the issues and concluded that in cases involving just one previous incident (the Ngyuen scenario) the jury must be sure to the criminal standard that the sole incident happened before they can consider whether they could be sure the defendant had the alleged propensity.
However, the position is different in cases where multiple instances of misconduct are said to demonstrate propensity. In that scenario, the jury should consider evidence about propensity in the round. It is not necessary to prove beyond reasonable doubt that each incident happened, nor must the facts of each individual incident be considered in isolation from each other. The proper issue was whether it was sure that propensity had been proved.
The Court took the view that it is unrealistic to expect jurors to “hermetically seal” each incident and that there is good reason for multiple incidents to be considered together; the allegations may corroborate one another because they are similar in nature and it may strike jurors as improbable that a number of allegations are false.
The Court endorsed the view expressed in Ngyuen that it is not necessary for a jury to collectively decide whether they are sure of propensity, but it was for each juror to follow their “own evidential path”. The Court emphasized that in order for a juror to take propensity into account they must be sure to the criminal standard that propensity exists Additionally it was stressed that Judges should always keep in mind that propensity is not the central issue in any trial and focus should not be distracted from the indicted offence.
The Court noted that trial judges retain a general discretion under the 2003 Act to exclude bad character evidence if its’ admission would be unfair. Exclusion may be particularly appropriate where there is a large volume of disputed allegations. This discretion, the court said, will be sufficient to safeguard against the dangers of distraction and prejudice.
The ruling has no real effect on defendants against whom the Crown wishes to adduce evidence about a single disputed incident; juries should continue to be directed that they can only consider the existence of propensity if they are sure that incident occurred.
For defendants facing multiple allegations of misconduct, the landscape has changed. Jurors will be directed that all they must be sure of is that propensity exists. Their analysis of the facts of the previous incidents can be holistic, they can rely one incident to corroborate another. The change heightens the stakes involved in an application to exclude or limit such evidence, for example on the grounds of unreliability, or where sheer volume or complexity of allegations makes the trial unfair. If the evidence is admitted the defendant now faces a greater risk of being found to have a propensity as the individual acts of previous misconduct alleged do not have to be proved to the criminal standard.