Applying the Moorov rule in a criminal trial does not involve a search for corroboration of the individual elements of a crime, but a search for a unity of purpose behind the accused's acting which makes it appropriate to treat the several incidents as part of a single course of conduct, the Criminal Appeal Court has ruled in a new decision.

The court held that the doctrine could be applied where an accused, CW, was charged with engaging in sexual activity with a male complainer (DA) then aged 15, with whom he was in a position of trust (Sexual Offences (Scotland) Act 2009, s 42), and with a course of sexual assaults against another male complainer (JW) to whom CW was an appointed "befriender", while he was then asleep and intoxicated (2009 Act, s 3).

It had been argued at trial for CW that DA's evidence was not capable of corroborating that of CW, as while the similarity of circumstances was not disputed, DA had been silent on whether he had been a willing participant or had consented, and whereas consent was not an issue for proof of the charge involving DA, but was an essential element of the charges involving JW which required to be corroborated.

The sheriff ruled that lack of consent was to be implied in the former charge, and could provide corroboration if the jury accepted JW's evidence regarding lack of consent, and directed the jury on that basis. On appeal it was argued that the sheriff had taken an erroneous view of s 42; evidence led in relation to that charge could not corroborate a lack of consent in relation to the s 3 charges, which was a critical matter for the Crown to prove.

Lady Dorrian, with whom Lord Bracadale agreed, held that evidence in respect of a charge where consent, or rather the absence of it, was not relevant "may properly be used to corroborate evidence of another complainer in respect of a charge where the absence of consent was a critical issue". Previous cases had clearly laid down that there was no requirement that the offences involved in an application of the Moorov rule required to be of the same name: "What one required to consider was whether there was an underlying similarity in the evidence indicating a consistent pattern or course of conduct such that it would be appropriate to consider the evidence of the witnesses as mutually corroborative."

Pointing out that in Moorov it was regarded as vital to consider the question as one of circumstantial evidence, she added: "If one bears that in mind, it is perhaps misleading to talk about a 'charge' being corroborated: what is being corroborated is the evidence of a witness in relation to a charge. The whole point about the doctrine is that the commission of each crime is only spoken to by one witness; the search is not for corroboration of the individual elements of the crime spoken to by an individual witness, but whether the nature of the evidence spoken to by the other witness is indicative of that underlying unity of purpose behind the accused’s acting which makes it appropriate to treat the several incidents as part of the one course of conduct.

"... where the offence is one, such as a s 3 offence, which has certain essential elements for its commission, the account of the complainer speaking to that charge would require to provide evidence from which all three elements could be established. Once he has given such evidence, however, his account may be corroborated by the evidence of the second complainer, without any requirement for the second complainer’s evidence to cover exactly the same essential elements."

However the sheriff's misdirection as to the role of consent in a s 42 charge was a material one, as the jury had effectively been given the impression that an element of evidence on which it was critical for JW to be believed was corroborated, and might have examined that aspect of his evidence less critically as a result. The appeal should therefore be allowed as respects the charges concerning JW (CW had pled guilty during the trial to the charge involving DA).

Lord Malcolm gave a separate opinion reaching the same conclusion.

Click here to view the opinions.