Keeping Up Is Hard to Do:
A Trial Judge’s Reading Blog


In R. v. Sutherland, 2022 MBCA 23, February 24, 2022, the Manitoba Court of Appeal noted that “the line between expert and lay opinion evidence can be difficult to draw…That will be demonstrated by a brief canvass of some of the authorities relating to opinion evidence of police officers” (at paragraphs 43 to 47):

Police officers have been permitted to express an opinion in the form of a compendious statement of facts when attempting to describe something pertinent to the case.  Those opinions are generally concerned with describing everyday matters of common experience such as indicating that a stain on a rug looked like a clean-up attempt was made…stating that shoeprints looked similar to the treads or shape of certain types of shoes…opining that footprints in the snow suggested the person was running…stating the general value of an item…and dealing with other mundane things such as describing a person’s demeanour…and recognizing a voice…As well, a firefighter has been permitted to explain how firefighters normally behave and to describe the style of jewelry.

Police officer testimony that has been found to exceed the proper bounds of lay opinion are opinions that a victim had never left town…certain cash payments are usually drug money…which involved the opinion of a border services official); the length of time spent at a truck window was indicative of a drug transaction higher than street level…and a cut on a finger looked like a bite mark…As well, in R v Lawrence, 2015 BCCA 358, leave to appeal to SCC refused, 36756 (14 April 2016), the Court concluded that an opinion, provided by a police officer using ultraviolet light, that dark marks were consistent with bruising was expert opinion evidence, as it “clearly exceeded the knowledge and experience of the ordinary person”.

There are also cases in which courts have allowed the expression of an opinion by a police officer in the form of a compendious statement of facts where the opinion is not concerned with describing everyday matters of common experience but, rather, with describing matters that are within ordinary officer training and experience.  Without these short-hand, police experience-based opinions, the trier of fact is unlikely to understand the significance of the individual facts described by the officer. 

As such, a long-standing fisheries officer has been permitted to describe boat movements and explain that they are consistent with fishing operations…a police officer has been allowed to describe a tool and state that it is suitable for breaking into vehicles…and a police officer, in what was described as a “rare” case, has been allowed to characterize a substance as cocaine. 

However, care must be taken when lay opinion evidence is based upon police experience, as it can be easy for a police officer to step outside the bounds of lay opinion, and provide an opinion which is normally given by an expert.  Distinguishing between lay opinion and expert opinion evidence is especially important when it is a police officer testifying because of the potential impact that a witness in the position of a police officer could have on a jury.