The evidence of certain classes of witnesses is insufficient, standing alone, as proof the facts deposed to. Such witnesses
- for example, accomplices, young children and complainants in sexual cases
- must usually be corroborated.
By corroboration is meant evidence other than that of the witness which is consistent with the witness's version of the facts and which tends to show the guilt of the accused.
To be of evidential weight the fact or facts corroborated must be material ones. Corroboration of insignificant facts will not usually help to strengthen the State case.
From the standpoint of the State what is important is for there to be "implicatory corroboration". By this is meant evidence that implicates the accused in the commission of the offence.
The corroboration can come from the evidence of another witness or from the evidence of the accused. The confession of an accused can be used as evidence corroborating other evidence. Even the failure of the accused to tell the truth can sometimes be corroborative of other evidence
In certain situations dealt with below, a "cautionary rule" applies. In these situations, the courts have to be aware of the dangers which arise from accepting certain types of evidence, especially if that evidence is uncorroborated. It is not enough that the court should warn itself on a token basis of the dangers of accepting these types of evidence. This warning must be put into practice by the court exercising great caution before accepting the evidence. In these situations, where there is a basis for doing so, the defence lawyer will obviously stress the dangers of reliance on the testimony.