Text in Afrikaans / Alhoewel die lokvalstelsel as misdaadbekampingsmetode lank reeds bestaan, is die toepassing daarvan nog altyd kontroversieE!I. Hierdie omstredenheid is die laaste paar jaar op die voorgrond gedryf deur 'n Regskommissie-ondersoek, sowel as deur die aanvaarding van 'n Handves van Menseregte. Ondersoek word ingestel na hierdie omstredenheid deur te kyk na die inhoud en toepassing van die stelsel, sowel as na die rol wat private persona, die polisie en die hot by die stelsel speeL Die gevolgtrekking waartoe gekom word, is dat die omstredenheid van die stelsel te danke is aan die feit dat dit verband hou met pro-aktiewe regshandhawing, wat in wese bestaan uit die gebruik van misleiding ten einde die pleging van 'n misdaad teweeg te bring. Die probleem met pro-aktiewe regshandhawing is dat dit 'n geleentheid skep vir die uitoefening van polisiediskresie wat grootliks sonder beheer geskied, met potensiele wanoptrede aan die kant van regshandhawers en die ondermyning van die publiek se vertroue in die billikheid van die strafregspleging. Ondersoek word gevolglik ingestel na metodes om diskresie-uitoefening by die lokvalstelsel te regverdig, aangesien daar wei ruimte is vir diskresionere magte wat behoorlik begrens, gestruktureer en gekontroleer is. Die vernaamste metodes van beheer oor diskresie­ uitoefening by die lokvalstelsel, naamlik die uitsluiting van getuienis en weerstand in 'n strafgeding, word grondig ondersoek met verwysing na die Engelse-, Amerikaanse- en Kanadese reg. Dit is egter die uitgangspunt van hierdie proefskrif dat wetgewende strukturering van diskresie-uitoefening by die lokvalstelsel die mees effektiewe oplossing bied vir meeste van die problema van die stelsel. Die enigste aanvaarbare basis waarop die lokvalstelsel kan funksioneer, is om deur middel van wetgewing die trefwydte van toelaatbare lokvaltegnieke en die beperkinge waarbinne regshandhawers regsonderdane mag beweeg om misdade te pleeg, te definieer. Daar is dus 'n behoefte aan die kodifisering van standaarde waaraan voldoen moet word voordat enige lokvaloperasie behoort te begin. / Although the system of trapping has long been used as a method of preventing crime, its employment has always been controversial. In the recent past, this controversy has come to the front due to an investigation by the South African Law Commission and the acceptance of a Bill of Rights. This thesis investigates this controversy by looking at the contents and application of the system, as well as the role which private persons, the police and the court play in the system. The conclusion arrived at, is that the controversy surrounding the system is due to the fact that it has to do with pro-active law enforcement, which consists of the use of deception to induce the performance of a criminal act. The problem with pro-active law enforcement is that it creates an opportunity for the exercise of police discretion which is mainly uncontrolled, with potentialmisconduct on the part of law enforcement officials and the subversion of public trust in the reasonableness of the criminal justice system. Consequently, methods by which the exercise of discretion in the system of trapping can be justified are investigated, since there is room for discretionary powers which are properly circumscribed, structured and controlled. The main methods of control over the exercise of discretion in the system of trapping, namely the exclusion of evidence and a defence in a criminal proceeding, are fully investigated with reference to English, American and Canadian law. Having considered the above, the conclusion is advanced that legislative structuring of the exercise of discretion in the system of trapping offers the most effective solution for most of the problems underlying the system. The only acceptable basis on which the system can function, is to define the scope of acceptable trapping techniques and the confines within which law enforcement officials may prevail on someone to commit a crime. This must be done by means of legislation. Accordingly, there is a need for codification of standards which have to be complied with before any trapping operation may commence. / Criminal & Procedural Law / LL.D. (Criminal & Procedural Law)

How should Australian criminal trial courts treat evidence deriving from illegally or improperly obtained evidence? The fact that derivative evidence gives rise to factors distinct from primary evidence makes it deserving of an examination of its peculiarities. In doing so, the assumption may be put aside that derivative evidence falls wholly within the established general discourse of illegally or improperly obtained evidence. Just as the judicial response to primary evidence must be intellectually rigorous, disciplined and principled, so must be the response to derivative evidence. As such, a principled analysis of how Australian courts should approach derivative evidence can significantly contribute to the discourse on the law with respect to the exclusion of illegally or improperly obtained evidence. This thesis provides that principled analysis by arguing that the principles which underpin and inform the discretionary exclusionary frameworks within Australia require an approach which is consistent as between illegally obtained derivative evidence and illegally obtained primary evidence.

Text in Afrikaans / Alhoewel die lokvalstelsel as misdaadbekampingsmetode lank reeds bestaan, is die toepassing daarvan nog altyd kontroversieE!I. Hierdie omstredenheid is die laaste paar jaar op die voorgrond gedryf deur 'n Regskommissie-ondersoek, sowel as deur die aanvaarding van 'n Handves van Menseregte. Ondersoek word ingestel na hierdie omstredenheid deur te kyk na die inhoud en toepassing van die stelsel, sowel as na die rol wat private persona, die polisie en die hot by die stelsel speeL Die gevolgtrekking waartoe gekom word, is dat die omstredenheid van die stelsel te danke is aan die feit dat dit verband hou met pro-aktiewe regshandhawing, wat in wese bestaan uit die gebruik van misleiding ten einde die pleging van 'n misdaad teweeg te bring. Die probleem met pro-aktiewe regshandhawing is dat dit 'n geleentheid skep vir die uitoefening van polisiediskresie wat grootliks sonder beheer geskied, met potensiele wanoptrede aan die kant van regshandhawers en die ondermyning van die publiek se vertroue in die billikheid van die strafregspleging. Ondersoek word gevolglik ingestel na metodes om diskresie-uitoefening by die lokvalstelsel te regverdig, aangesien daar wei ruimte is vir diskresionere magte wat behoorlik begrens, gestruktureer en gekontroleer is. Die vernaamste metodes van beheer oor diskresie­ uitoefening by die lokvalstelsel, naamlik die uitsluiting van getuienis en weerstand in 'n strafgeding, word grondig ondersoek met verwysing na die Engelse-, Amerikaanse- en Kanadese reg. Dit is egter die uitgangspunt van hierdie proefskrif dat wetgewende strukturering van diskresie-uitoefening by die lokvalstelsel die mees effektiewe oplossing bied vir meeste van die problema van die stelsel. Die enigste aanvaarbare basis waarop die lokvalstelsel kan funksioneer, is om deur middel van wetgewing die trefwydte van toelaatbare lokvaltegnieke en die beperkinge waarbinne regshandhawers regsonderdane mag beweeg om misdade te pleeg, te definieer. Daar is dus 'n behoefte aan die kodifisering van standaarde waaraan voldoen moet word voordat enige lokvaloperasie behoort te begin. / Although the system of trapping has long been used as a method of preventing crime, its employment has always been controversial. In the recent past, this controversy has come to the front due to an investigation by the South African Law Commission and the acceptance of a Bill of Rights. This thesis investigates this controversy by looking at the contents and application of the system, as well as the role which private persons, the police and the court play in the system. The conclusion arrived at, is that the controversy surrounding the system is due to the fact that it has to do with pro-active law enforcement, which consists of the use of deception to induce the performance of a criminal act. The problem with pro-active law enforcement is that it creates an opportunity for the exercise of police discretion which is mainly uncontrolled, with potentialmisconduct on the part of law enforcement officials and the subversion of public trust in the reasonableness of the criminal justice system. Consequently, methods by which the exercise of discretion in the system of trapping can be justified are investigated, since there is room for discretionary powers which are properly circumscribed, structured and controlled. The main methods of control over the exercise of discretion in the system of trapping, namely the exclusion of evidence and a defence in a criminal proceeding, are fully investigated with reference to English, American and Canadian law. Having considered the above, the conclusion is advanced that legislative structuring of the exercise of discretion in the system of trapping offers the most effective solution for most of the problems underlying the system. The only acceptable basis on which the system can function, is to define the scope of acceptable trapping techniques and the confines within which law enforcement officials may prevail on someone to commit a crime. This must be done by means of legislation. Accordingly, there is a need for codification of standards which have to be complied with before any trapping operation may commence. / Criminal and Procedural Law / LL.D. (Criminal & Procedural Law)