Reasonable Grounds for Arrest Made Out
R. v. Debot,  2 S.C.R. 1140: The police received confidential information from an informant concerning a future drug deal. The informant had previously provided useful information to the police (Cst. G) and was considered by the police to be reliable. The informant provided details said to have been received directly from one of the parties to the drug transaction indicating date, time, location, type of drug, and names of the parties to the offence. The police established visual surveillance of the anticipated site of the drug deal; a vehicle known to the police was observed along with persons entering/exiting the premises; Cst. G, by radio to an off-site officer (Sgt. B), confirmed that the accused was the registered owner of the vehicle. Sgt. B then instructed other officers to intercept and search the vehicle. On these facts Cst. B had reasonable and probable grounds to believe that the accused had drugs in his possession, despite reliance on hearsay from other officers. An officer instructed to carry out a search by another officer is entitled to assume that the officer ordering the search has reasonable grounds.
The tip provided by the informant was compelling and detailed: it went beyond mere rumour; the informant was reliable and not paid nor facing charges; and the police surveillance corroborated the information received.
R. v. Wong,  3 S.C.R. 36 (obiter conclusion on reasonable grounds for arrest for unlawful gaming): The police entered a recently vacated
room which revealed that the furniture had been rearranged to be "suitable for gambling"; located many slips of paper in a garbage bin written in Chinese characters; the slips were similar to other notices known to be distributed elsewhere in the city; hotel records showed that the accused had rented the same room on two other occasions that month.
R. v. Storrey,  1 S.C.R. 241: Reasonable grounds to arrest for aggravated assault made out by accused’s possession and ownership of a relatively unusual and uncommon car of the type used during the crime; (b) the accused had been stopped by the police on several occasions driving that car; (c) the accused had a past record of violence; and
(d) the accused closely resembled the picture of another person picked out by the victims as their assailant.
R. v. Stillman,  1 S.C.R. 607: Reasonable grounds to arrest for murder made out where
(a) he was the last person seen with the deceased on the evening of her disappearance;
(b) he could not, or at least did not, account for his whereabouts between 9:00 p.m. and 11:30 p.m. on that evening when he returned to his residence; (c) when the appellant returned home he was wet and cold, his clothes were muddy and he had a scratch over his eye and blood on his face consistent with having been in a scuffle. When the deceased’s body was found she appeared to have been physically beaten; (d) the appellant claimed to have been in a fight with some "Indians" but this story changed over time; (e) the appellant’s worried and disturbed reaction to the police helicopter which was searching the river close to where the deceased was found; (f) immediately following the appellant’s observation of the helicopter he left a suicide note and fled; (g) the appellant made a statement to Constable Cole saying, "I tried to stop her from killing herself. I left her there"; and (h) the RCMP received a report from two motorists that they had seen the deceased on the bridge crossing the Oromocto River and that she was with a male who met the description of the appellant (para. 31).
R. v. Latimer,  1 S.C.R. 217: Reasonable grounds to arrest for murder made out.
Objectively, the reasonable person in the position of the arresting officer would have concluded there were reasonable grounds for arrest. Those grounds included:
the carbon monoxide in Tracy’s blood, strongly suggesting that she had been poisoned; the fact that it was extremely unlikely that Tracy’s death had been accidental; the fact that, because of Tracy’s physical condition, her death could not have been suicide; and finally, the fact that the accused had both opportunity and motive (para. 27).
R. v. Warford, 2001 NFCA 64: The police received a "tip" that the accused would be driving to a local nightclub, at a particular time, to sell cocaine...