Criminal charges generally require proving intent. It's very hard to prove what somebody knew.

What you can do is make it illegal to buy particular materials, and then the intent to break that law becomes obvious.

As I understand it after having been informed by authoritative sources over a significant period of time, they should just say "no".

You honestly believe a scrapyard owner should go to jail for buying metal that might be stolen?

Fines, sure. But "long prison sentences"?

> this problem would vanish in short order.

Anyway that's worked well for drug abuse/sales, so it should probably work here too

Once pharmacies and drug manufacturers in the American legal system started getting held liable for excessive opioid prescriptions and pushing, it became less common. So yeah. It might work.

Same with pawn shops.

> Same with pawn shops.

Isn't America experiencing absurd amounts of petty theft right now? Maybe pawn shops are no longer in the equation (doubtful, though. Any data on this?) but did it actually help alleviate the problem?

As for the opioid crisis... well, I don't want to open up that can of worms.