Luxury-goods broker has “100 percent risk-free” plan to poison a target with ricin (a deadly toxin that has no known antidote and is undetectable in an autopsy), which he purchases on the Dark Net for $300 in Bitcoin and has delivered to Manhattan post office box. Surprise! The seller is actually an FBI agent (and ricin is not actually delivered). Broker: the Biological Weapons Act can’t possibly prohibit a single, local murder; federalism and the Commerce Clause say so. Second Circuit: Conviction affirmed.