Corroborating evidence is a modern evidence law concept used in furtherance of the administration of justice. The exact meaning of the term is, however, unclear, which is why the concept can be described as both vague and ambiguous. Accordingly, the aim of this thesis was to examine this type of evidence with the help of functional analysis.
The examination was performed in four steps. First, the concept of corroborating evidence was examined theoretically, which meant analysing the ways in which this concept relates to associated concepts in evidence law. The second step consisted of two empirical studies which examined the prevalence and actual use of corroborating evidence. Next, the concept of corroborating evidence was analysed from the point of view of comparative law by means of a study on corroboration rules in English law. Finally, the function of corroborating evidence was examined from an epistemological perspective.
The examination reveals that corroborating evidence refers in general to uncertain circumstances. When circumstances lack clear relevance, there is a risk that they will be ascribed an incorrect function and therefore also a wrong probative value. The empirical study also shows that two types of corroboration are confused, i.e. convergent corroboration and credibility corroboration. Two conclusions can be drawn from the foregoing: one, that a structuring approach to evaluation of evidence is of greatest importance, and two, that a more restricted definition of corroborating evidence is not possible. In addition, it has been demonstrated that in some cases decisions were made without the requirement for corroborating evidence and in other cases corroborating evidence was required.
Since this inconsistency in judicial practice cannot be explained by reference to the principle of free evaluation of evidence, or to be regarded as compatible with the principles of equal treatment, legal security and rationality, the overall conclusion of the thesis is that the concept of corroborating evidence should no longer be used in Swedish law.