Because a criminal is going to want to give over their thumb print. Honest, law abiding citizens would be hesitant to do this. Criminals... Heck no.
the criminal can just say, 'I'm not going to do this, I'm going to sell it at a shop in Sarpy County,'"
So, this is to force criminals to go to Sarpy County to sell their unregistered weapons. Sure. As if the only place a criminal can unload a gun is in a law abiding second hand guns shop.
I think there's a case of the Stupefying Flu going around because it looks like it is contagious.
“Omaha police say it will help cut violence, by taking illegal weapons off the street.”
Nary a mention of returning a stolen firearm to its rightful owner. Do the police actually do that any more?