This month’s topic is "corroboration."

One of the fundamental rules of Scots criminal law is that the essential elements of the charge require to be corroborated before anyone can be convicted on that charge. There are exceptions to this rule, but they are few and far between and usually involve only minor statutory charges. The same rule does not apply South of the border, where rules of evidence and procedure are very different.

Corroboration does not require two witnesses. What it does require is two or more separate sources of evidence. It is the different source that matters, not the type of evidence. These sources could be oral from witnesses who saw or heard something, admissions by the accused or “real” evidence such as fingerprints or blood.

It follows that an admission by the accused is not enough evidence to convict in Scotland because that evidence needs to be corroborated from another source. This is entirely different in England, where corroboration is not required. I note that most of the recent high profile convictions that have been overturned in England relied on uncorroborated confessions. It also does not matter how many times he confesses or to how many people as all the confessions emanate from only the one source i.e. the accused.

There is an exception to this rule which first came to light in the case of Peter Manuel who strangled a number of people in the Fifties. If the confession contains details that could only be known to the perpetrator of the crime, then the confession may corroborate itself. In Manuel’s case, he knew where the bodies were buried. It is for this reason that the police do not give out details of a crime so that any confession cannot later be attacked by claiming the details had been read in a newspaper.

As to the amount of corroboration required, that will depend upon the strength of the primary source. An admission does not need much. One recent murderer was convicted on his confession to having drowned the victim being corroborated by having wet trousers when arrested. A weaker piece of evidence will need better corroboration. It is a case of weaving the threads together to make a rope strong enough to support the case. If the threads are thin [the evidence is weak] more are needed.

Why do we need corroboration at all? Simply because people are fallible. The witness could be mistaken or have misunderstood and this is a valuable check on the accuracy and reliability of their evidence. In short it makes it more difficult to convict and thus less likely that the innocent will be convicted. It is an essential safeguard in our system of justice.

It has an adverse effect as well. One can be perfectly confident that the accused committed the crime but he cannot be convicted, as there is no corroboration. This is a serious problem in domestic violence cases. Undoubtedly as a direct result of the corroboration rule in Scotland more violent partners get away with it than they would if it happened in England. This is totally unacceptable. Unfortunately bad cases make bad law. So far the establishment view is that removal of the essential safeguard that is corroboration, even if it means that domestic abusers are not punished and their abused partner not protected, is not justifiable.

This is a serious and complicated problem. If to protect victims the corroboration rule is to be loosened or removed, in what circumstances should this be allowed? Are there boundaries to it? Should it be restricted to spousal abuse given the large number of unmarried households? If not, is there some limit to whom it may apply? For example at present no one would consider that someone entering your home and assaulting you should be considered a case of domestic abuse but those cases may also not be able to be proved because of lack of corroboration. How do you differentiate? Does the attacker have to be living with you, and if so for how long? What is the position if the victim is particularly vulnerable? What if it is the accused who is vulnerable?