TAVIS & The Charter: Acting on a Hunch
In discussing their search for a person of interest, Doucette quotes the TAVIS officer as stating:
“This guy is probably carrying drugs or he could be carrying a gun,” Hayward says. “All I know is that when he sees us, he runs.
“We need to find out why he’s running and for that we need to catch him,” he adds.
From these comments it is clear the officer has no reason to pursue this individual beyond being concerned that he may be doing something wrong. It seems like the officer is acting on a hunch, or a gut feeling, and really has no basis beyond that for his belief.
In R. v. Mann, 2004 SCC 52, the Supreme Court’s seminal decision on investigative detention, Justice Iacobucci stated, in no uncertain terms:
35 Police powers and police duties are not necessarily correlative. While the police have a common law duty to investigate crime, they are not empowered to undertake any and all action in the exercise of that duty. Individual liberty interests are fundamental to the Canadian constitutional order. Consequently, any intrusion upon them must not be taken lightly and, as a result, police officers do not have carte blanche to detain. The power to detain cannot be exercised on the basis of a hunch, nor can it become a de facto arrest.
Obviously the Sun article, clearly written as an informative piece, raises some major concerns about Charter rights. There is a real problem here.
An individual can be convicted of a criminal offence based on the testimony of one witness. The trier-of-fact, of course, would have to believe the witness, and be convinced of the guilt of the accused beyond a reasonable doubt. It happens quite often that a crucial witness to a Crown’s case has somewhat of a questionable background. This is where an unsavoury witness warning, called a Vetrovec warning, comes into play.
In R. v. Pelletier, 2012 ONCA 566, Justice Watt provides a useful refresher of how a jury should be instructed in assessing the evidence of such a witness:
 First, as a matter of general principle, the evidence of a single witness is sufficient to support a conviction of any offence other than treason, perjury or procuring a feigned marriage: R. v. Khela, 2009 SCC 4,  1 S.C.R. 104, at para. 2.
 Second, where proof of the guilt of an accused rests exclusively or substantially on the testimony of a single witness of doubtful credit or veracity, the danger of a wrongful conviction is especially acute: Khela, at para. 2. Thus, in jury cases, we try to ensure that the jury understands when and why it is unsafe to rest a conviction on the unsupported evidence of witnesses to whom descriptors like “unsavoury”, “untrustworthy”, “unreliable”, or “tainted” apply: Khela, at para. 3. Such an instruction, a Vetrovec caution, is not mandatory in judge alone trials: R. v. Snyder, 2011 ONCA 445 (2011), 273 C.C.C. (3d) 211, at paras. 24-25.
 Third, where a Vetrovec warning is provided, in appropriate cases the trial judge should also draw the attention of jurors to evidence capable of confirming or supporting the material parts of the otherwise untrustworthy evidence: Khela, at para. 11.
 Fourth, to be confirmatory of the testimony of an unsavoury witness, evidence must come from another source and tend to show that the unsavoury witness is telling the truth about the guilt of the accused: Khela, at para. 37; R. v. Kehler, 2004 SCC 11,  1 S.C.R 328, at para. 15. Confirmatory evidence must be independent of the tainted witness, but need not implicate the accused: Khela, at paras. 39-41; Kehler, at para. 16. Where the only issue in dispute is whether an accused committed the offence, the trier of fact must be comforted that the tainted witness is telling the truth in that regard before convicting on the strength of the tainted witness’ testimony: Khela, at para. 43; Kehler, at para. 20.
 Fifth, after considering the totality of the evidence, a trier of fact is entitled to believe the evidence of a disreputable witness, even on disputed facts that are not otherwise confirmed, if the trier is satisfied that the witness, despite his or her frailties or shortcomings, is truthful: Kehler, at para. 22.
 Finally, at least in the absence of evidence of collusion or collaboration, the evidence of one unsavoury witness can confirm the testimony of another: R. v. Roks, 2011 ONCA 526, (2011), 274 C.C.C. (3d) 1, at para. 67.