Materiality. R v Vassel
In R v Vassel (Ont CA, 2018)the Court of Appeal provides a definition of materiality:
 Materiality. An item of evidence is material if it is offered to prove or disprove a fact in issue: Luciano, at para. 207. Whether an accused said to have committed an offence as a principal was present at the scene of the offence is a fact in issue.