The authority of the police to seize items of an evidentiary value that are in “plain view” has a long history in our shared common law. Though certain elements of the plain-view doctrine have developed differently in Canada and the United States of America, the authority of the police to seize evidence pursuant to its parameters remains a well-accepted police investigative power.
The essence of the doctrine is quite simple: if in the course of their duties, the police see an item that will afford evidence, they generally can seize it. In Canada, it has been pointed out that “plain view seizure is a common law doctrine that permits the police to seize evidence of a crime or contraband without a warrant” (R. v. Ahmed, 2022 ONCA 640, para. 66). In the United States, the plain-view doctrine has been described as incorporating the “commonsense principle that the Fourth Amendment doesn’t normally require an officer to ignore what he sees lying before him” (Bovat v. Vermont, 141 S.Ct. 22 (Mem) (2020), at 23). In Ireland, it has been pointed out that “on searching in good faith if gardaí come across evidence as to another crime (one other than the crime for which the warrant was issued), be that a drug-cultivation plant in a house or a bloodied knife or a computer thought related to that separate crime, that object or those objects may also be seized” (Director of Public Prosecutions -v- Quirke  IESC 5, para. 88).
Historically, what was or was not in plain view was usually not difficult to differentiate. However, when this seizure power is applied to electronic devices, such as computers and cellular telephones, this differentiation is no longer without difficulty. For instance, is anything not on the screen when the device is opened in plain view? Accordingly, the question that arises is whether this historic and long-standing police power can be adapted to police searches of modern technology.
It has been suggested that applying the plain-view doctrine “to digital evidence represents a misunderstanding of the nature of modern computer searches and gives the police wide latitude to search and retain any information found on a computer.”
Professor Jørgensen explains that the “plain-view doctrine requires that evidence of criminality be ‘immediately apparent’—can the police perceive evidence of criminality in a medium where they need complex computer tools to ‘see’ the information contained?” (Id. at 803). As will be seen, the answer to this question may depend, in part, on how we define “immediately apparent.”
In this column, I intend to review a recent decision of the Supreme Court of Canada (R. v. McGregor, 2023 SCC 4,  1 SCR 1) in which the application of the plain-view doctrine was considered in the context of a search of a computer. Interestingly, the investigation and the initial search took place in the United States.
I will commence with the historical context of how the plain-view doctrine began and then look at its development in Canada and the United States. I will then review the Supreme Court of Canada’s decision in MacGregor.