Supreme Court

Regina v Mitchell

[2016] UKSC 55; [2016] WLR (D) 541

2016 July 7; Oct 19

Lord Kerr of Tonaghmore , Lord Clarke of Stone-cum-Ebony , Lord Hughes , Lord Toulson , Lord Hodge JJSC

Crime — Evidence — Similar facts — Propensity — Defendant admitting killing victim with knife but claiming self-defence — Evidence adduced of previous incidents where defendant threatened people with knives — Earlier incidents not leading to convictions — Standard of proof required to show propensity — Whether jury needing to be satisfied beyond reasonable doubt that earlier incidents occurred — Criminal Justice (Evidence) (Northern Ireland) Order 2004 (SI 2004/1501), arts 6(1), 8


The defendant admitted that she had killed her ex-partner by stabbing him with a knife but claimed she had acted in self-defence. At her trial the prosecution adduced disputed evidence of other incidents in which the defendant was said to have attacked or threatened to attack a person with a knife but which had not been the subject of any criminal convictions. The prosecution relied on that evidence to show that the defendant had a propensity to use knives in circumstances where she had neither been provoked nor been acting in self-defence. The defendant was convicted of murder but the Court of Appeal in Northern Ireland allowed her appeal on the ground that the judge ought to have directed the jury that, before they could take the disputed bad character evidence into account, they had to be sure of its truth. The Crown appealed, challenging the Court of Appeal’s ruling that the non-conviction bad character evidence had to be proved beyond a reasonable doubt if it were to be considered by the jury on the issue of propensity.


Held, appeal dismissed. The proper issue for the jury was whether they were sure that the propensity had been proved beyond a reasonable doubt. Consequently, when a sole incident was involved the facts of that incident had to be proved to the criminal standard. However, when there were several incidents relied on the jury did not have to be convinced of the truth and accuracy of all aspects of each of the alleged incidents. The facts of each alleged individual incident did not have to be considered in isolation from the others as, in such circumstances, the evidence about propensity should be considered cumulatively. Further, it should be made clear to a jury that propensity was an incidental issue which could not alone establish guilt and the most important evidence was that which bore directly on the guilt or innocence of the defendant of the offence for which she was being tried.. In the instant case the trial judge had failed to give adequate directions as to how the question of propensity should be approached by the jury and, accordingly, the conviction was unsafe and had properly been quashed (paras 39, 43–44, 46, 49, 52, 54–57). Per curiam. While reliance on cumulative past incidents in support of a case of propensity may indeed illuminate the truth of the indicted allegations, excessive recourse to such history could skew the trial in a way which would distract attention from the central issue and undermine the fairness and efficiency of the trial by introducing satellite litigation. That is an important consideration to be borne in mind by trial judges when determining applications to adduce evidence of propensity (para 53).

Appellate History

Decision of the Court of Appeal in Northern Ireland [2015] NICA 34 affirmed on different grounds.


Liam McCollum QC and David Russell (both of the Northern Ireland Bar) (instructed by Public Prosecution Service for Northern Ireland, Belfast) for the Crown.

Frank O’Donoghue QC and Sean Devine (both of the Northern Ireland Bar) (instructed by KRW Law LLP, Belfast) for the defendant.

Reported by: Ms B L Scully, Barrister

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