Appeal Court decision highlights perils with illegally obtained evidence

By John L. Hill

Law360 Canada (May 2, 2023, 10:21 AM EDT) --
John Hill
John L. Hill
Criminal lawyers often refer to the “poisonous tree doctrine” in formulating a defence to criminal charges, often having to do with wrongful seizure of evidence in drug cases. The metaphor has nothing to do with the toxicity of the substances seized but everything to do with the notion that if the source of the evidence (the “tree”) is tainted, then everything gained from that source (the “fruit”) is tainted as well. Under this doctrine, derivative evidence from an illegal search, arrest or questioning becomes inadmissible.

Carrying on with the metaphor, the Ontario Court of Appeal has recently held that the poisonous tree does not necessarily have to be felled; some pruning will suffice.

On April 28, a three-judge panel of the Ontario Court of Appeal handed down its decision in R. v. Nguyen 2023 ONCA 291. The case dealt with a situation where two Toronto police officers on bicycle patrol in the Parkdale neighbourhood of Toronto were supposedly investigating a reported firearm discharge that occurred 11 days prior. Kevin Nguyen was walking down the street when he was spotted by the cops on bikes. Nguyen was known to police to have been involved in previous firearms incidents and was suspected of being a member of the Parkdale Crips street gang.

The officers stopped Nguyen and advised they were investigating an LCBO theft. Nguyen was grabbed and placed under arrest without being told the reason. When Nguyen resisted, he was punched twice in the torso and when he was down, one officer jumped on his back. A third officer in the vicinity came to the other officers’ assistance. When searched, police found powder and crack cocaine on his person. Nguyen was ushered to the third office’s cruiser and while handcuffed, he was punched in the stomach and thrown headfirst into the cruiser. He required hospitalization.

Unbeknownst to the two original officers, police were attempting to obtain a search warrant on an address suspected to be Nguyen’s home. All that was missing was confirmation that the place to be searched was Nguyen’s apartment. With confirmation of the address given by Nguyen when arrested on the street, police attended the apartment to “freeze” it and await a telewarrant for a full search. Once an officer obtained keys but before the search warrant was issued, police entered the apartment, made a visual search, found nothing and left after 45 seconds. Later in the evening, Nguyen’s arrest for drugs and confirmation of address, a search warrant was issued. This time a loaded handgun was found as well as “proceeds of crime.” Both Nguyen and his mother were charged with weapons offences.

At trial, the drug charges were thrown out when a Charter challenge dealing with improper arrest and illegal search was successful. The trial judge also held the freeze was unreasonable. There were no exigent circumstance requiring the first apartment entry. Defence counsel brought a Garafoli application to try to strike the search warrant used in finding the gun (R. v. Garafoli [1990] 2 S.C.R. 1421).

The court could not overlook the behaviour of police but conceded that the 45-second search could be excused to prevent destruction of evidence that might exist before the valid search was undertaken.

Even though there might be a connection with the earliest search and the later full search of the property, the excesses of police would not block the admission of the evidence of a gun being found. Afterall, the police had not relied simply on brutality and false information to obtain the search warrant; they also had information from a confidential source that would justify the intensive property search.

Counsel for Nguyen argued that Charter rights cannot be ignored if police are untruthful in giving evidence even if another affiant, in this case a confidential source, provides information that would justify the issuance of a warrant. The Court of Appeal held that as long as the affiant is unaware of the misconduct of his fellow officers and there is nothing to put him on notice that enquiries should be made to ascertain if there were other material facts, the warrant is valid and the evidence collected under it stands.

The purpose of rejecting the fruits of the poisonous tree is to provide a safeguard against improper police tactics and obtaining evidence by illegal means. It is a safeguard to ensure the public’s respect for our institutions of criminal justice. Providing an exception to ignore bad policing and overlook discreditable conduct, even while acknowledging wrong has been done, gives power to those who would choose to infringe citizen rights in future. It’s just pruning the branches of the poisonous tree.

John L. Hill practised and taught prison law until his retirement. He holds a J.D. from Queen’s and LL.M. in constitutional law from Osgoode Hall. He is also the author of Pine Box Parole: Terry Fitzsimmons and the Quest to End Solitary Confinement (Durvile & UpRoute Books), which was published Sept. 1. Contact him at

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