The way the comment was phrased makes it sound like they're bringing in the guns from outside the country.
The thing I am objecting to is the notion that if an illegally used gun was used in a crime it must have once been a legally possessed gun, and (the implicit policy prescription) that the way to curb illegal gun possession is by limiting legal gun possession. While that last part probably tracks, because of my ideological beliefs, I'd rather we exhaust all other options before limiting legal gun ownership. And even then, again because ideology/convictions, curbing legal gun ownership is probably not a thought I'd entertain at the ballot box.