A criminal defence lawyer says Toronto's proposed handgun ban isn't likely to keep illegal firearms out of the hands of criminals.

On Sunday, 29-year-old Faisal Hussain opened fire with a handgun on Toronto's Danforth Avenue, killing two people and injuring 13.

A confidential police source told CBC News the firearm has been traced to the United States, and that Hussain may have taken it from his comatose brother, who has alleged ties with a street gang.

By 2017, about half the guns used for crime in Canada originated from domestic sources, with the rest largely flowing across the U.S.-Canadian border, according to Toronto police's guns and gangs unit.

​​Jordan Donich, a criminal defence lawyer in Toronto, spoke with As It Happens guest host Laura Lynch about gun control. Here is part of their conversation.

Just how hard is it to get an illegal gun in Toronto if you want one?

There's different ways of getting an illegal gun. One can purchase it on the streets from perhaps a dealer or somebody that actually sells guns illegally on the streets.

Other ways are people who actually steal guns from legal gun owners.

Do you have any sense of how many of these illegal guns, the ones that aren't taken from legal owners, are flowing through the city right now?

I personally don't have a sense of that but I can tell you the issue starts at the border. That's where the weapons are coming from.

They're imported from the U.S. because it's easy to get guns in the U.S.

You can buy guns [from illegal, dark web sites] online from here in Canada and ship them to a PO box in the States, drive across the border and bring them across.

Police Chief Mark Saunders speaks to Toronto City Council, which passed a motion to ask the federal government to ban the sale of handguns within city limits.

But then you're smuggling them illegally. You're hoping you don't get caught.

That's right, but the truth is a lot of people don't get caught. And if they do get caught it's on the 10th time, not the first time.

So if you know this a problem, if the police know this is a problem, if the border service agents know it's a problem, then why aren't they doing a better job of checking for guns coming across the border?

We want to get it at the beginning of the chain, not at the end. And it probably comes down to resources, right?

Then you get into the whole counter-argument: Well, who do we target? What vehicles do we look? Do we search every vehicle?

Once a gun is on the streets, can it be traced?

It depends whether or not it's serialized and that's kind of, I think, the issue we're having. A lot of these weapons have been deserialized. They're invisible guns.

Kaya Malcolmson, right, and Jowa Malcolmson, left, organize flowers at a memorial site remembering the victims of the Toronto shooting. (Mark Blinch/Canadian Press)

So is there anything the police can do at that point to try to trace where the gun came from?

We have to ask ourselves, OK what's the point? So they trace, they find out where the source was, they find it was a store in the U.S. The store owner's going to say, "I sold it to a person legally here in the U.S."

That's not the problem. The problem is the trafficking.

Ok, but you also hear the reports of people in Canada buying guns legally in order to turn around and sell them. Have you heard of cases like that?

Personally, no. We haven't defended cases like that. But guns are like anything else that can be bought or sold, just like drugs. People go and take out prescription drugs and sell them. It's the same issue we have as a society.

A woman writes a message in honour of the victims of the Danforth shooting. (Mark Blinch/Canadian Press)

Toronto city council passed a motion calling for a ban on the sale of handguns in the city. Given all you've just told us about access to illegal handguns, what do you make of the motion?

Even if it were to go through, we have to ask ourselves: Is it going to actually have any meaningful impact on crime?

The issue here is crime, not lawful gun owners going to the shooting range and locking their guns up safely and protecting them.

The problem is the unlawful weapons. So banning handguns isn't, I think, going to have a lot of impact on violent crime because the handgun used in the violent crime generally are not legal.

So what's the answer then?

The answer is really at the border and controlling the flow of weapons illegally into Canada.

Written by Sarah Jackson and Sheena Goodyear. Interview produced by Imogen Birchard. Q&A edited for length and clarity.