Updated: Feb 20
The Defendant Sean Patrick Mackey was initially charged with residential break and enter and wearing a mask with intent to commit theft. The Defendant was acquitted by the trial judge after it was decided that two separate search warrants issued for the Defendant’s home and his DNA sample violated the Defendant’s right to be free from unreasonable search and seizures pursuant to s 8 of the Charter.
There were a series of three break and enters, all with DNA evidence that suggested that the three crimes shared a perpetrator. The DNA from the break and enters was also linked to a DNA sample found in a stolen truck from a previous crime scene. The Defendant’s fingerprint was identified in this stolen truck.
The police then applied for, and were granted a search warrant of the Defendant’s home to search for evidence linking him to the break and enters. The police argued the following as reasons for reasonable and probable grounds to believe that the Defendant was the perpetrator of the break and enters:
1) The DNA evidence found at the crime scenes matched the one in the stolen truck,
2) a fingerprint on the stolen truck was known to belong to the Defendant and,
3) the perpetrator as shown in surveillance footage and a previously taken mugshot of the Defendant looked like the same person to the police.
The search of the Defendant’s home resulted in evidence incriminating the Defendant of breaking and entering.
Following the search of the Defendant’s home, a warrant for the Defendant’s DNA sample was issued based on the same grounds as the ones relied on for the home warrant, as well as the incriminating evidence from the search of the Defendant’s home.
The Defendant’s DNA matched the DNA evidence found in the stolen truck and at the scenes of the break and enters. However, the trial judge found that both the warrant for the Defendant’s home and the warrant for his DNA failed to establish that police had reasonable grounds to believe that that the Defendant was the perpetrator of the break and enters. As a result, the incriminating evidence gathered from the search of the Defendant’s home and of the Defendant’s DNA sample were excluded.
This appeal is only concerned with the trial judge’s ruling of the DNA warrant and of the decision to exclude the DNA evidence.
1. Did the trial judge misapply the standard of review when reviewing the DNA warrant?
The Court held that the trial judge erred in excluding the DNA evidence due to the trial judge’s misapplication of the standard of review of a warrant. A new trial was ordered for only the following counts that were concerned with the DNA evidence: three residential break and enters and wearing a mask with intent to commit theft.
The appropriate standard of review to apply when reviewing DNA warrants require judges to consider whether there are reasonable grounds to believe in the following:
a) an offence occurred,
b) DNA evidence was found at the crime scene or at a location that has been associated with the crime,
c) the person subjected to the warrant was a party to the crime and
d) a forensic DNA test could be able to show whether the DNA evidence from the crime scene and the DNA sample gathered from the person subjected to this warrant could be from the same person.
The perspective that a reviewing judge should take is one that asks whether the issuing judge could have found that there were reasonable grounds to issue the warrant. The judge reviewing a previously issued warrant cannot quash the warrant based on the fact that they wouldn’t have issued the warrant themselves.
This Court found that the trial judge quashed the warrant because they would not have issued the warrant themselves. After applying the standard of review from the correct perspective, this Court found that the issuing judge could have been satisfied that there were reasonable grounds to issue the warrant.
At conflict is whether the issuing judge could have had reasonably inferred that the Defendant was a party to the offense. This standard does not require an issuing judge to be convinced of the Defendant’s guilt beyond a reasonable doubt.
The DNA evidence found in the stolen truck matched DNA evidence found at all three crime scenes. It’s evident that the Defendant was in the stolen truck at one point since he was one of two people who were confirmed to be in the stolen truck. This Court concluded that the Defendant’s fingerprint being in the same stolen truck as an unknown DNA sample that matched the DNA evidence collected at the scene of the offence could provide the issuing judge enough evidence to reasonably infer that the Defendant was a party to the offence.
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 R v Mackey, 2020 ONCA 466 at paras 2, 3.  Ibid at para 13, 14.  Ibid at para 14.  Ibid at para 15.  Ibid at paras 21, 23.  Ibid at para 22.  Ibid at para 24.  Ibid at para 26.  Ibid at para 28.  Ibid at para 43.  Ibid at para 45.  Ibid at para 46.  Ibid at para 46, 55.  Ibid at paras 47, 48.  Ibid at para 80.  Ibid at para 52.  Ibid at para 54.  Ibid.  Ibid at para 56.  Ibid at para 70.  Ibid at para 57.  Ibid at para 66.  Ibid at para 69.  Ibid at para 68.  Ibid at para 67.