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3. Investigation and interrogation

In this session, we will look at how certain police investigation and interrogation techniques might clash with rights. In the course of the investigation, the police may be authorized to take steps which, if not strictly justified, would unlawfully intrude with the liberty of citizens. The Supreme Court has recognized that, short of arrest (see previous session), there is such a thing as short term "investigative detention" and an attendant power to search a suspect. There is a significant case law about the sort of warrantless searches that the police can conduct outside someone's home or without actually searching individuals. The question is how much information the police can glean from outside for example through sniffer dogs, heat detection cameras, hydro bills or wiretaps. All of these are crucial for investigative purposes and fall short of more coercive means of investigation, but concerns about privacy remain. The courts will review the evidence that was submitted to justify wiretapping carefully, for example, although as always will try to strike a balance between the rights protected and the legitimate demands of criminal investigations.

It is important to distinguish between pre-arrest and post-arrest interrogation. Before someone is arrested, they may be asked questions in the course of an investigation. The Supreme Court has recognized that this flows from the possibility of "investigative detention." By the time they have arrested someone, the police have more significant prerogatives. The goal of an interrogation is to reveal evidence and a degree of manipulation is part of that exercise. However, certain techniques are clearly off limits. The most obvious example would be torture but even without going that far, Canadian courts have been wary of interrogation techniques that involve bullying or trickery. The so-called "Reid technique" has come under attack in both Canada and the US as highly problematic, even more so when used against mere witnesses.

Note: this session is connected to subsequent sessions on exclusion of evidence, entrapment, and imaginary offenses all of which will be examined in detail later.
Class Preparation:
"…it may seem counterintuitive that people would confess to a crime that they did not commit…however, this intuition is not always correct. A large body of literature has developed documenting hundreds of cases where confessions have been proven false by DNA evidence, subsequent confessions by the true perpetrator, and other such independent sources of evidence.”

Justice Iacobucci, R. v. Oickle, [2000] 2 S.C.R. 3 at para. 35.