[<< wikibooks] Canadian Criminal Evidence/Character/Alternative Suspect Evidence
== General Principles ==
The defence may attempt to raise a doubt by suggesting that the offence was committed by a third-party.
The defence can only be raised where there is sufficient evidence to connect a third-party to the offence. This will turn on the question of sufficient relevancy and probative value. The alternative suspect must have sufficient provable connection to the offence and cannot simply be speculative.
The evidence cannot simply be evidence of propensity or suggestive of a hypothetical motive.However, a specific propensity to commit a particular offence can be sufficient.The accused must show that there is an air of reality to the defence of another suspect. There must be a basis upon which a properly instructed jury could acquit.The greatest danger to the defence by raising this sort of evidence is that it permits the crown to present reply evidence that it would not otherwise be allowed to adduce. Where evidence of an alternative suspect is raised, there is a risk that the trier of fact would be left with the wrong impression about the insufficiency of the investigation. 
As such, the crown will be permitted to lead evidence on the investigative process that includes hearsay and bad character evidence of the accused.