In an article about the lawsuit against Jay Wallace, owner of a sporting goods store in Smyrna, Georgia:

Since Bloomberg became mayor in 2002, every gun homicide in the city has been committed with an illegal gun, police say.

But it's too difficult to go after and get the ones with illegal guns. Much easier to control those who follow the law.

I don't know many specifics about this particular case, but the charge is basically that the shop's practices allow straw purchases.

Well, either the shop complies with the law or it doesn't. Should be simple enough to determine.

And, as Caleb points out, what a "straw purchase" is gets constantly misrepresented.