This thesis examines the interpretation of section 35(5) of the Constitution of the Republic of South Africa, 1996, which empowers the courts to exclude unconstitutionally obtained evidence in criminal trials. A generous and purposive interpretation should be at the heart of the admissibility assessment. This work explores the threshold requirements and the substantive phase of the interpretation of section 35(5). Given that this provision is manifestly modelled on the terms contained in section 24(2) of the Canadian Charter, the manner in which the courts of that country have grappled with the interpretation of section 24(2) has been accorded particular importance. As a preliminary issue, the courts must consider whether the threshold requirements of section 35(5) have been satisfied. It is concluded that the courts of South Africa have interpreted the threshold requirements of section 35(5) in a broad manner, thereby making it less onerous to satisfy, compared to the threshold requirements contained in section 24(2) The substantive phase of the admissibility assessment should consist of two legs that must be clearly separated from each other, for the reason that the assessment in each leg of the analysis serve to enhance different societal interests. The public interest in protecting the rights of the accused should be the central consideration during the first leg, while the societal interest in convicting the guilty should be contemplated during the second leg. The first leg of the analysis is concerned with the effect that admission of the evidence would have on the fairness of the trial. It is suggested that the trial fairness requirement should be determined by means of a conscription analysis. The prosecution may rely on the ‘discoverability’ doctrine or on the ‘independent source’ exception. The admission of evidence based on these exceptions would not render the trial unfair. Such an infringement would, accordingly, not add to the seriousness of the violation. Conversely, although admission would tend to render the trial unfair, the evidence should not ‘automatically’ be excluded. However, such an infringement should be regarded as a serious violation, since section 35(5) was designed to prevent unfair trials. The second leg is focused on the effect that either the admission or exclusion of the evidence would have on the integrity of the criminal justice system. It is concluded that the ‘current mood’ of society should not be determinative of the admissibility assessment. The following overall admissibility framework is recommended: Despite the fact that admission would render the trial unfair, the courts should be allowed to consider police ‘good faith’ and other factors ordinarily considered during the second leg, in order to make an admissibility ruling. Differently put, a balancing exercise should be performed, in which the factors identified in the seminal case of Collins are considered and weighed at the end of the analysis. More importantly, the seriousness of the violation should be a significant factor in the overall admissibility assessment, since judicial condonation of serious infringements would generally impact negatively on the repute of the criminal justice system. / Thesis (LLD)--University of Pretoria, 2010. / Centre for Human Rights / unrestricted