Depending on the seriousness of the crime, the taxman may or may not be able to share those details with law enforcement.
I think the cutoff is if the sentence could be for 14 years, they can share it.
When Canada legalized marijuana, they made many infractions punishable by up to 14 years. So if you sell unlawful marijuana to a minor, you could get 0 to 14 years in prison. As a result, many illegal marijuana sellers will require ID to avoid this (dunno if they’re paying taxes or not, but makes sense to care about this if they are).
I mean, the theft itself is obviously unlawful. But perhaps you wouldn't be taxed on theft proceeds anyway, so no tax laws are broken in that case.