The standard argument in favour of mandatory minimum sentences is that they deliver certainty. "If you do X, the minimum punishment you will receive is Y." It's simple, clear, and predictable. And that makes mandatory minimum sentences a powerful deterrent against crime.

The standard response to that argument is: "Look at the research. There's stacks of it. It proves that mandatory minimum sentences don't deter crime."

The standard response to that standard response is, well, nothing. Supporters of mandatory minimums simply ignore the research on deterrence. So let's save a little time today and skip it.

Go back to the initial claim that mandatory minimums produce clarity, simplicity, and predictability. "Do the crime, do the time." Is that true?

No. And I can demonstrate with two provisions in the Conservatives' omnibus crime bill.

The bill includes a mandatory minimum sentence of six months for growing more than five and fewer than 201 marijuana plants with the intent of trafficking. There's also a mandatory minimum sentence of nine months for anyone who grows between one and 201 marijuana plants for the purposes of trafficking when certain factors are present - among them, that "the person used real property that belongs to a third party in committing the offence."

Justice minister Rob Nicholson says these changes don't target recreational pot smokers. No, the government is targeting "traffickers."

And we all know who traffickers are. They're bikers, gangsters, and depraved people who lurk outside schoolyards. Or so the minister suggests in every interview.

But what Nicholson never mentions is the legal definition of "trafficking." It includes selling marijuana for profit, as anyone would expect. But profit isn't essential to the definition. Simply giving marijuana to someone is "trafficking." So is offering to give them marijuana.

So anyone who passes a joint to a friend is a "trafficker." In fact, anyone who offers a joint to a friend is a "trafficker," even if the friend declines the offer. (There are a lot of "traffickers" in Canada. Some of them are members of Parliament.)

Now look at that first mandatory minimum sentence again: It means that anyone who grows six marijuana plants with the intention of sharing even a single joint with a friend will be guilty of an offence punishable with a mandatory minimum sentence of six months in jail.

And remember the phrase "real property that belongs to a third party"? That's what a rented apartment is. Imagine a university student living in a rented apartment with her boyfriend, suggests University of Toronto criminologist Tony Doob. She grows a single marijuana plant. She rolls a joint for her and her boyfriend. And just like that she's a "trafficker" subject to a mandatory minimum sentence of nine months in jail.

Are these outcomes simple, clear, and predictable? Hardly. They're shocking as hell. But mandatory minimums have a nasty tendency to do that.

Remember the infamous case of the pizza thief sent to prison for life in California? The law didn't say "pizza thieves shall get a life sentence." The law said anyone convicted of a third felony would get a life sentence. Pizza theft is normally a misdemeanour. But that poor sap had committed previous felonies and a different law said that petty theft committed by anyone convicted of felonies must be prosecuted as a felony. So misdemeanour pizza theft became his third felony and he was sent to prison for life - an outcome almost everyone thought was insane.

Of course the justice minister will protest: Gardner is spinning fantasies, he will say. No reasonable prosecutor would convict that hapless university student knowing that she would be hit with a minimum nine-month sentence. He would charge her with a lesser offence. Or drop it altogether.

But Doob calls that argument "specious." The bill is clear. If passed by Parliament, it is the will of Parliament. Prosecutors may say it is not their place to frustrate the clearly expressed will of Parliament. Which is a reasonable thing to say.

And notice how strange it is for the government to rely on the discretion of prosecutors to keep their mandatory minimum sentences from producing injustices. After all, the whole point of mandatory minimums is to do away with discretion. That's their appeal. "If you do X, the minimum punishment you will receive is Y." No ambiguity or uncertainty. It's all perfectly clear and predictable.

But mandatory minimums don't actually do away with discretion.

They merely transfer it from judges, by restricting their ability to choose the sentence, to prosecutors, who choose the charge. The system is still ambiguous, uncertain, and unpredictable. It's just ambiguous, uncertain, and unpredictable in a different way.

Mandatory minimums are a fraud.