Report No. 94
10.9. Symmetry and development of the law.-
In justification of a rule or discretion for excluding illegally obtained evidence, there is also an argument resting on what may be called the symmetry and development of the law. The argument can be put thus, in brief. If the judge does not even have the option of excluding evidence obtained by illegal search and seizure it means that such conduct will seldom be scrutinised in the courts. The legality of the police conduct will not, then, be a live issue is criminal trials, there will be no stage at which police officers may be cross-examined with regard to the propriety of their actions and there will be no incentive for defense counsel even to raise such issues.
The law of search and seizure will continue to develop only haphazardly (if at all), through rare civil actions for trespass brought against police officers, or in the rather inappropriate context of prosecutions that may be brought for the "obstruction" of a constable acting in the execution of his duty. In contrast a rule or discretion of exclusion may help the symmetry of the law and its proper development.