Double criminality is really a fundamental base of extradition. The principle is that we will not extradite to, and other countries will not extradite to us, unless we're satisfied that whatever the person is charged with in that country would also be a crime in our country.
That is assessed in Canada under something called a conduct test, which means that we look at the evidence that has been provided to us about the crime and we ask this question: If we had that same evidence of conduct in Canada, would a criminal offence arise from that conduct?
The approach is flexible because it takes into account the fact that the way an offence is characterized in one country might be different. If you say the offence is called “this”, we might not call it the same thing, but it might still be a criminal offence here. By looking at the conduct rather than the name of the offence, we have a lot more flexibility.