determine whether the arrest of the respondent, on DCE, was
a lawful arrest.
 I begin with this court’s decision in Brown v. Durham
(Regional Municipality) Police Force (1998), 43 O.R. (3d) 223,
 O.J. No. 5274 (C.A.), which addressed the common law
police power to arrest an individual in order to keep the peace.
This power derives from what is commonly referred to as the
Waterfield test that is discussed in Brown.1 In order to exercise
that common law power, Doherty J.A. said, at para. 61:
That approach requires first, that the police be acting in the execution of
their duties and second, that in all the circumstances, the police conduct
constitutes a justifiable interference with individual liberty.
 There is no doubt that in this case the police were acting
in the execution of their duties. They had a duty to keep the
peace and protect the public in an area that had a history of conflict. They had been called on many times to carry out that duty
and they had developed policies and protocols to accomplish
their task. No issue is taken with the efficacy of those policies
 The central issue is whether the arrest of the respondent
was a justifiable interference with his individual liberty. Every
person has constitutionally protected rights including “freedom
of thought, belief, opinion and expression”: s. 2(b) of the Charter.
However, the public as a whole has a right to peace and security.
Where there is the potential for a conflict between the two, there
is never an easy answer as to which should triumph. As Doherty
J.A. noted in Brown, at para. 62:
The infinite variety of situations in which the police and individuals interact
and the need to carefully balance important but competing interests in each
of those situations make it difficult, if not impossible, to provide pre-
formulated bright-line rules which appropriately maintain the balance
between police powers and individual liberties.
 The police have a duty to keep the peace. They also have
a duty to protect individuals from harm. “To serve and protect”
is not just a convenient slogan. It reflects the central role of the
police. As Rouleau J.A. said in Figueiras v. Toronto (City) Police
Services Board (2015), 124 O.R. (3d) 641,  O.J. No. 1515,
2015 ONCA 208, 320 C.C.C. (3d) 437, at para. 88: “[k]eeping the
peace and preventing property damage or personal injury are
clearly important duties”.
1 R. v. Waterfield,  3 All E.R. 659,  1 Q.B. 164 (C.A.).