Legality of purchase vs. possession

There’s a nuance here I don’t understand. Hypothetically, let’s say that I choose to purchase some illicit thing like illegal drugs, firearms, someone’s kidney, etc.

I can certainly see that actually having a pound of cocaine would be illegal because that thing is illegal and it is in my possession. But legally speaking, is the act of purchasing an illicit thing itself a crime? If I go on Ebay and buy that kidney, can the cops kick down my door right then? Or do they have to wait for the Fedex truck to show up with the kidney?

Most broadly, in what legal sense can the government constrain my ability to spend my money?

Depends whether engaging in a transaction is a crime, or is it only for the seller.

If the two of you agree on a price, that could be conspiracy to traffic in whatever? (But perhaps consipracy to traffic only applies to trafficking-sized quantities).

I know in Canada, one fellow locally was charged for taking money to tell (undercover) police who would sell them drugs. It would not surprise me if the laws are written so any sort of participation in drug trafficking, especially, is grounds for prosecution.

And that’s what I’m getting at, really. Is there a law somewhere that says, “Thou shalt not purchase illicit stuff?” Or does that law say, “Thou shalt not possess illicit stuff”, and we can nab people during the transaction simply because that’s good enough to demonstrate an intent to break the law as regards possession?

Is there room for a wedge between these two things?

It depends on which law you are talking about. Some things are illegal to purchase, some to possess, and some to both purchase or possess.

If drugs were only illegal to purchase, the cops could pull over a guy with 300 pounds of cocaine in his back seat and not be able to do anything because there is no evidence that he purchased it (perhaps he is a mule).

Likewise, if only possession was against the law, you could have a notarized purchase order from Jimmy the Squealer authorizing a wire for 300 pounds of cocaine and you couldn’t touch him because it was never in his possession.
A bit more in depth discussion (Canadian law)

Whereas I find this: (Canadian Law, YMMV)

Basically, unless buying or soliciting is specfically a crime, the usual offenses seem to olny relate to the act of disposing of the substance, not acquiring it.

Well when you propose such a straightforward and obvious example it kind of makes me wonder why I even had this question in the first place.

Of course you are right. Both possession and purchase must be explicitly illegal in some sense or the door would be open to cleverness of the sort you describe.

Also, thanks for the links md2000. I was more interested in the American end of things but it’s always good to know how others see these things.