In R. v. Moses, 2010 ABPC 344 the police responded to a call about a disturbance, and arrived at an apartment suite, where a man was cleaning up glass outside. He directed them into the apartment and toward a bedroom down a hall. When the police entered the bedroom, the accused was lying down on a mattress eating soup from a bowl. At trial, one officer testified that he entered the bedroom to see if anyone was hurt or committing an offence. Thereupon, a scuffle ensued and the accused spat her soup at two officers, and kicked a third. At trial, the Court found that the police may have had lawful authority to enter the apartment suite, but not the bedroom. The accused was acquitted on the basis that there was no legal authority for the police to enter the bedroom and no authority to detain the accused. The lawful execution of their duties requirement was therefore not proven in the charges of assaulting police.

In Canada, individuals have traditionally enjoyed the right to be free from government interference, absent any lawful authority to the contrary. Therefore, excluding grounds for arrest, it is often said that the police lack the power to interfere with an individual’s free movement. This makes the definition of arrest critical in the balance of power between individuals and police officers or private citizens attempting to make an arrest: See R. v.  Delong (1989), 47 C.C.C.(3d) 402 (Ont. C.A.) 417, Section 29(2) of the Criminal Code.

Underlying the duty to inform a person of the reasons for his or her arrest or detention are two principles: (1) a person is not obliged to submit to an arrest or detention if he or she does not know the reason for it and (2) the right to counsel can be exercised in a meaningful way only if the person knows the extent of his or her jeopardy: see R. v. Evans (1991), 63 C.C.C.(3d) 289 at 302-03 (S.C.C.).

The entitlement of a person who is the subject of an unlawful arrest to resist that arrest by the use of reasonable force is recognized by Justice E.G. Ewaschuk, in Criminal Pleadings & Practice In Canada, 2nd ed. (Aurora: Canada Law Book Inc., 2000)  at 5:

 A person unlawfully arrested by a peace officer is entitled to resist such unlawful arrest by reasonable force since the officer is not acting in the lawful execution of his duties: See also Section 34(1) and 37(1) of the Criminal Code.

According to Justice Anderson of the Alberta Provincial Court:

47. In this case, police entered the suite itself based on the implied consent of the person sweeping up glass and the unidentified female near the kitchen.48. The evidence does not establish that police took any steps to determine whether either of those persons had control of the suite or had any authority to grant entry. A simple question would have answered that. That said, the persons with whom the police spoke showed some indicia of care or control. Thus the Court finds that the officers could reasonably believe that their entry into the suite itself was consensual.

49. The police officers’ entry into the bedroom is another matter.

50. The person occupying the bedroom, the accused, did not give permission to the officers to enter the bedroom and there is no evidence that police received permission to enter from anyone who had authority to grant such permission. At the time of entering the bedroom, police had no idea as to whether either person with whom they had spoken, had any control over the bedroom. One of the officers leading the way acknowledged under cross-examination that he realized many kinds of living arrangements can exist and that it is common for bedrooms to be rented out. The evidence at trial shows that if police had taken the time to ask, they would have learned that the female with whom they spoke did not purport to have any right of entry into the bedroom herself.

51. The Court is not satisfied that police entered the bedroom with any valid consent.

And on the issue of the power to detain, the Court held:

67. The more difficult issue is whether police can detain a person for investigative purposes, inside of a dwelling if police are in the dwelling with lawful authority derived from some other source. If, for example, police are in a dwelling with the bona fide consent of the person whose privacy interests are affected, and seek to detain someone for investigative purposes within that context, there would seem to be no logical reason why the powers described in R. v. Mann, supra, would not exist. Similarly, there might be a power to detain an individual within a dwelling, for investigative purposes, if the person is present when a search warrant is being executed. Neither of those situations exist in this case however. Any authority the officers may have had to enter the bedroom ceased at the point when the officers could see that the occupant was safe, a determination that could be made within seconds.