True, they do not follow laws. Hence, they are 'criminals'.
But the thing is, those guns don't start out as criminal tools.
They are a legal product....the moment it becomes a 'legally-defined' gun at a factory owned by somebody.
That somebody is responsible for any harm it causes.
Until, that somebody is no longer the owner-of-record.
That means, when it is sold to a wholesaler or a retailer......the liability of ownership transfers to the new owner.
The retail gunshop or wholesaler is then liable for any harm that high -lethality tool creates while they still own it. That means, if theives break into the shop and steal guns....and those guns are used to shoot school-kids, the gunshop has a share of the liability for those injuries.
But if that doesn't happen and the retailer sells one or more to Jo Fabeetz, homeowner, or business owner, or hobbyist.......well, guess what?
Joe becomes the owner-of-record.