There was a darkweb hitman, but it was really amateur hour stuff: https://invidious.perennialte.ch/watch?v=cln7leXuJnY Drug trafficer paid some teenagers to kill a cop in Russia IIRC. Only known instance of assassination with the help of the darkweb.
Nice/retro video on the difference between the darkweb and deepweb: https://invidious.protokolla.fi/watch?v=c9XkgOfadts I knew all this years ago, but nice to have a video about it. Also mostly part of the deepweb (not findable by search engines): IPFS, Arweave, unindexed IA and YT things.