R V Waterfield - Opinion of Court

Opinion of Court

Ashworth J., for the Court, held that the charge of assault was invalid and quashed the convictions of Waterfield and Lynn. To come to this conclusion, Ashworth made an important analysis of the requirements needed to show that a police officer was in the execution of his duties.

In most cases it is probably more convenient to consider what the police constable was actually doing and in particular whether such conduct was prima facie an unlawful interference with a person's liberty or property. If so, it is then relevant to consider whether (a) such conduct falls within the general scope of any duty imposed by statute or recognized at common law and (b) whether such conduct, albeit within the general scope of such a duty, involved an unjustifiable use of powers associated with the duty. Thus, while it is no doubt right to say in general terms that police constables have a duty to prevent crime and a duty, when crime is committed, to bring the offender to justice, it is also clear from the decided cases that when the execution of these general duties involves interference with the person or property of a private person, the powers of constables are not unlimited.