When to give a Vetrovec caution

A Vetrovec caution is not made mandatory simply because the complainants’ evidence was essential to the Crown’s case: R v Boone, 2016 ONCA 227 at para 53

 

The hallmarks of classic Vetrovec witnesses: jailhouse informants, accomplices, people who stand to benefit in from their testimony: Boone at para 50

 

The Nature of the Vetrovec Instruction

In deciding whether to believe some, none or all of a vetrovec witness' it is necessary to see if the balance of the evidence provides “some independent confirmation.” This evidence need not directly implicate the accused in the offences; it need only be capable of restoring the trial judge's faith in the relevant aspects of the witness' account MacIsaac at paras 37-38

In looking to confirmatory evidence, the trial judge cannot rely upon neutral evidence - this neither confirms nor discredits the vetrovec witness' testimony: MacIsaac at para 37 

A trial judge need not evaluate each item of evidence for its potential confirmatory value; instead, confirmatory evidence can be identified in a review of the evidence as a whole: MacIsaac at para 41

Appellate Review

A trial judge has a discretion whether to give Vetrovec warning and as to the nature and extent of the warning. The exercise of that discretion is entitled to substantial deference on appeal: Boone at para 51; R v Van Every, 2016 ONCA 87 at para 73

 

Similarly, when engaging in the "independent confirmation" analysis, trial judges are afforded considerable latitude. The extent to which a trial judge illustrates potentially confirmatory evidence in connection with a Vetrovec witness is largely a matter of judicial discretion: MacIsaac at para 39

While not determinative, the failure of trial counsel to object to the content of a vetrovec instruction in a jury charge is an important consideration, suggesting that, in the context of the trial, the instruction that was given was considered adequate: Van Every, at para 76; Boone at para 53