Guilty because I believe you are — A Case of Confirmation Bias

In R. v. Aslami 2021 ONCA 249 the Ontario Court of Appeal overturned a very serious case: the firebombing of an occupied residence.

The case is important for a number of reasons, including the Court’s affirmation that text messaging evidence must be scrutinized carefully before it is utilized.

For me, the case is important for another key reason; it is a case that typifies confirmation bias.

In short, confirmation bias is the tendency to accept or ignore evidence in order to conform with one’s theories or beliefs.

In this particular case, the decision maker erred when he put weight on certain evidence, specifically, text messages and weak video identification evidence.

It is likely that by the time the judge was required do an overall assessment of the case, he had already made up his mind about the guilt of the accused. You can tell this by the fact that he ignored three key pieces of evidence which were as follows:

• that the Appellant stole the vehicle involved in the firebombing before he actually had a motive to commit the offence (the Crown’s explanation was maybe it was stolen twice in a 24-hour period) (para 45);
• that the clothing of the Appellant and the perpetrator did not match (para 38) but this fact was ignored by the judge;
• that the Appellant’s es-wife identified the Appellant by how he moved in the CCTV footage she observed. The problem with this evidence was that this is not what the ex-wife said (para 41).

This case, for me, is a classic confirmation bias case. There were key pieces of evidence that needed to be explained, analyzed and seriously considered. They were not because, at least by me estimation, the judge fell into confirmation bias reasoning.

Perfection is not the purview of human judges.