I honestly don't know where you have to go to learn to conduct arguments like this, it's utterly baffling to me.
A reminder that the initial point I was responding to, and the topic of the discussion (at least as long as I've been part of it), was (paraphrasing) "if the level of criminality of immigrants is at the same level as natives, then there's no argument against allowing them in" (and bear in mind this was a claim made in immediate response to a list of rapes and murders I believe). My retort was that one should expect much lower levels of criminality from immigrants, precisely because it's entirely in the interest of the host nation to select the best, or at least people who aren't committing crimes.
So yes, it's completely irrelevant to ask me to now define what "crime" even means, or at which arbitrary point I would place a dividing line between "acceptable" and "unacceptable" crime, because none of that (apparently) needed to be clarified in the initial claim I was responding to.