The Exclusionary Rule: An Analysis

Evidence can be obtained in many different ways. Although the use of evidence is to prove that someone has committed a crime, it is possible for that evidence to be obtained through the process of crime. The Exclusionary Rule, section 24 of the Canadian Charter of Rights and Freedoms, prevents the usage of illegally obtained evidence. Moreover, a high risk factor that may lead to the obtaining of illegal evidence is the cellphone. This composition will explore the risks and the full meaning of the exclusionary rule.

Although dedicated to bringing justice to their city and country, it is inevitable for law enforcement personnel to break laws they fight to protect. The “Fruit of The Poisonous Tree,” also known as the Exclusionary Rule, protects suspects by excluding illegally obtained information as legitimate evidence as it interferes with their basic human rights. This paper first explicates the Exclusionary Rule in detail, the Rule’s relationship to its American counterpart, as well as issues regarding how the evolution of technology might influence the Rule’s application and effects.

What counts as illegally obtained evidence? A classic example is when a police officer goes into a suspect’s house to find evidence of a bank robbery and instead/also finds a piece of evidence that the suspect is dealing illegal drugs. Regardless if the police officer has a warrant to search the suspect’s house for evidence of a robbery, the evidence of drug dealing is not useable. Consider this clause in Section 24(2) of the Canadian Charter of Rights and Freedom:

“Where, in proceedings under subsection (1), a court concludes that evidence was obtained in a manner that infringed or denied any rights or freedoms guaranteed by this Charter, the evidence shall be excluded if it is established that, having regard to all the circumstances, the admission of it in the proceedings would bring the administration of justice into disrepute[.]”  (Charter of Rights and Freedoms, 2018)

The important word here is “disrepute”: Justice as an ideal in a representative democracy like Canada requires that its Justice system be administered with an exacting standard of compliance to its stated rules, laws, and most importantly, its most noble values. The Charter’s main purpose was to codify, such that our Justice system could efficiently defend Canadians’ most dearly held ideals Although criminals obviously are not reputable citizens, in a country like Canada which is based on ideals of Justice, it is reasonable that ALL Canadians be protected by the law;the law should not limit the right to equality, no matter the reputation of the person or the nature of the crime committed. (Evidence, 2017)

Illegal evidence is classified into different categories, each of which can determine remedies for those impacted by it: Primary evidence, Secondary evidence, and Derivative evidence. In a murder case, primary evidence may be when a police officer sneaks into the suspect’s house with the intention of finding a body and being successful. Secondary evidence is when a police officer intends to find only a body, but ends up also finding the murder weapon, for example a bloodstained knife; the knife will count as secondary evidence as it was a result of an illegal search for only a body.(Evidence, 2017) Derivative Evidence  is related to secondary evidence in that it is also a result of the search for primary evidence: instead of finding a bloodstained knife directly, the police officer searches the suspect’s phone and finds out that the suspect disposed of the knife in his neighbour’s backyard; this intel on the location of the knife is classified as derivative evidence. Although these categories seem fairly settled in terms of legal precedent, in Canada they are not as stable and reliable as many people assume. (Evidence, 2017)

Both the Canadian and American Justice systems have struggled to deal with illegally obtained evidence, but the American position is comparatively clear in terms of precedent, while Canadian courts continue to struggle with this issue. Unlike the Canadian Charter, the American Constitution, and more specifically the Bill of Rights, specifies in some detail exactly how illegal evidence is to be classified, and how the courts should deal with it. The Fourth Amendment’s allusion to the “fruit of the poisonous tree” has become a legal metaphor in the American court system, and is essentially a more useful definition of the Exclusionary Rule. This metaphor was established to illustrate that as long as the tree itself is tainted, all of the flowering fruits are also tainted; apropos, derivative evidence, as defined above, is not admissible evidence because it is gained from illegally obtained primary evidence, i.e. the tree, a poisonous tree. The metaphor  has been adopted by the American courts to signify evidence which has been tainted as a result of a Constitutional violation, which has a weight and substance in the American system such that there is no room for misinterpretation.

American courts do include a few exceptions that state that evidence is admissible if

  1. The evidence was obtained through an untainted and direct source.

E.g. Information provided by an anonymous caller on the location of a murder weapon.

  1. The evidence inevitably would be found.

E.g. The police officer went into the suspect’s house and found the murder weapon without a warrant despite the fact he would be granted a warrant in a few days.

  1. The search warrant was not found to be valid based on probable cause but was executed by government agents in good faith (called the good-faith exception).

E.g. The police officer acted based on a strong belief that what he was doing was legal, without the knowledge that his given warrant is subsequently declared invalid.

While many exceptions to the Exclusionary rule have arisen in American courts, the majority have been rejected. American courts have also clarified that primary, secondary and derivative evidence will be treated identically, as they are all evidence that is subject to the application of the Exclusionary rule. (Bederman, 2017) Interestingly, most Americans believe that the laws of the United States are more pro-defendant compared to those of other countries, and are urging American lawmakers to consider practices of other countries where the police are afforded greater leeway. Judge Wilkey, a Circuit Judge of the United States Court of Appeals for example, has argued that “one proof of the irrationality of the Exclusionary rule is that no other civilized nation in the world has adopted it.” On the other hand, Professor Bradley,  a former professor of psychology and neuroscientist at the University of Chicago,  notes that in adopting a new Charter of Rights and Freedoms, Canada “chose not only to copy the U.S. Fourth Amendment virtually verbatim, but also to adopt, as a constitutional requirement, the much-maligned Exclusionary rule, albeit in a more limited form.” (Citation needed)

The Canadian Charter might in part be derived from the American Constitution, but while American courts believe uphold the Exclusionary rule with minimum exceptions,  Canadian courts prioritize the Justice system’s reputation over dealing with illegally obtained evidence consistently. Whether and in what circumstances courts in Canada should exclude illegally or improperly obtained evidence is one of the most hotly contested questions in criminal procedure and evidence law. The purpose of section 24(2) of the Charter is not to identify and penalize law enforcement officials for unconstitutional behavior, although this result may be a by-product of the exclusionary remedy; instead, it was incorporated to prevent the courts from being brought into disrepute by allowing evidence obtained through questionable means to stand. (Bederman, 2017)  In addition, as can be seen in the structure of section 24(2), the Canadian approach, unlike the American one, incorporates a two-step process of determining when evidence is to be excluded. First, the evidence must have been obtained in a manner that infringed or denied a right or freedom guaranteed by the Charter. After the infringement requirement has been satisfied, the second step is to determine whether the admission of the evidence would bring the administration of Justice, the courts, into disrepute. (Bederman, 2017)   However, the good-faith exception on the part of police has been acknowledged to significantly minimize the consequences of illegal conduct regarding investigative evidence. If police officers reasonably rely on existing authority for the purposes of an investigation, and their conduct is later found to be unconstitutional, courts will be much less likely to allow an exclusion of the evidence obtained. On the other hand, where police knowingly disregard the law in order to collect evidence, the action will be considered a serious offense and courts will be much more likely to exclude the evidence.

Another difference between the Canadian and American approaches is the status of evidence immediately after it has been held to be the “fruit” of unconstitutional conduct. While the American approach immediately acknowledges illegally obtained evidence as unlawful and prevents it from being admissible, in contrast, the Canadian approach acknowledges that the evidence is obtained illegally, however, it will not deny its use in court until it has been proven that using this evidence will bring the administration of Justice into disrepute, a clearly problematic difference for defendants in Canada. s stated above, the purpose of the American Exclusionary rule is to prevent law enforcement officials from engaging in unconstitutional activitiesthe purpose of the Canadian exclusionary rule is to prevent the court from being brought into disrepute. This notably different purpose significantly affects the administration of justice. (Bederman, 2017)  The Exclusionary approach is justified in the American system to prevent the police from employing unconstitutional conduct; therefore, the application of the American Exclusionary rule is necessary in order to achieve its original purpose, to protect anyone from a violation of their rights, without prioritizing the reputation of the court over an evident obstruction of justice when handling illegally obtained evidence. (Don, 2017)

Technological ferment also significantly complicates how the Exclusionary rule can be applied. Section 8 of the Canadian Charter of Rights and Freedoms tells us that everyone has the right to be protected from “unreasonable search and seizure.” (Bederman, 2017)  How would this apply to a cell phone? A police officer may not enter your house without your permission or a legal warrant or that they may not take any of your belongings without an explanation, such as that it may have be a stolen object; however, with cell phones, though it can be seized by the authorities, it is practically useless if the internal contents cannot be accessed. In December 2014, a decision by the Supreme Court of Canada allowed the police to search some information in cell phones without a warrant when making an arrest. This controversial ruling is the first to consider cell phones as part of a search relating to an arrest. It recognizes that unlike most other objects, cell phones require special consideration because they are stores of private informationOn the other hand, once someone’s phone is taken by the police, they are not allowed to search the content, unless given the permission to look at certain applications, such as the telephone app, to examine call histories, or the messages app to find texts that may involve illegal activity, and must record exactly what they are looking at and doing with the phone. They may not access applications that are unrelated to the search itself, meaning that if the police officer is only authorized to look at a call history, they may not access any photos. Moreover, if the seized cell phone has a passcode that locks the content, the owner of the phone can choose not to give it away. However, even if the owner refuses to give the passcode, law enforcement officials, if given permission by the judge, are allowed to unlock the phone by hiring hackers, or via forensics to obtain a fingerprint.  

So how does the Exclusionary rule apply to cell phones?  Cell phones are the perfect example of a “tainted tree”, and its contents “the fruits”. If a police officer were to make a note of all the contacts in a cellphone, but accidentally clicked into an application which he believed to be the contacts app, and instead found text messages illustrating the location of an illegal drug trade, the information is subject to the Exclusionary rule as the officer was not authorized to access the application where he found the message. As a result, this information must be brought into court and to go through the two-step process to determine whether or not it can be used as evidence. With technology such as cell phones causing commotion by advancing at a rate faster than what the law can keep up with, it is inevitable that more issues will arise from the birth of new technology. (Don, 2017)

Finally, the Exclusionary rule is an important part of the Canadian and American justice systems, because it is supposed to provide protection to anyone while preventing the authorities’ illegal conduct. Although the methods of preventing illegally obtained information differ between the US and Canada, it is clear that the establishment of the Exclusionary rule should be steadfast and its application consistent; however, in practice, the Canadian two-step process leads to ambiguous results as to whether or not a certain piece of evidence can be used. Most problematically, in response to the never-ending ferment of technology, new inventions and improvements to existing technologies will furhter complicate the application of the Exclusionary rule, and requires a more thoughtful systemic response. (Don, 2017)



Evidence and Exclusionary Rule in Serbian Criminal Proceedings. (2017). Journal of Forensic Sciences and Digital Investigation, 1–7.

Don, S. (2017). Part V Rights and Freedoms, B Rights and Freedoms under the Charter, Ch.38 The Charter and Criminal Justice. The Oxford Handbook of the Canadian Constitution.

Bederman, D. J. Constitution-Making and Ancient History. The Classical Foundations of the American Constitution, 95–175.

Exclusionary Rule. The Supreme Court A to Z.