In assessing whether a police officer has reasonable grounds to justify the arrest, what is the test for reasonable grounds?

[14] In assessing whether an officer has reasonable grounds to justify the decision to arrest, the reviewing court should take into account that police officers are trained and entitled to draw on their training and experience to make deductions and inferences from facts known to them: R v. Cunsolo 180 C.R.R. (2d) 174 at para. 68(6).

[15] Not every unlawful arrest is an arbitrary arrest. In circumstances where the person making the arrest has an honest, though mistaken, belief that reasonable grounds exist for arrest and there is some rational basis for such belief, the arrest cannot be said to be arbitrary though it may be unlawful: R v. Duguay, 18 D.L.R (4th) (C.A.) at para. 25 affirmed 56 D.L.R (4th) (S.C.C.).

[16] In circumstances where, viewed objectively, a peace officer’s grounds fall short of the required reasonable and probable grounds but are sufficient, when viewed objectively, to constitute reasonable suspicion, the peace office may detain the person for investigative purposes: R v. Mann (2004), 2004 SCC 52 (CanLII), 185 C.C.C (3d) 308 (S.CC) at para. 45.