How would an assassin get enough polonium-210 to murder someone?

Question

Title.

Answer 1

Purchase it

Answer 2

A government agency would provide, without cost, polonium to the assassin.

Likely after that assassin received some meaningful level of training of how to handle the stuff without self-injury!!

My wife says I'm more likely to die from the anti-freeze she puts in my coffee.....

Answer 3

All you need of that stuff to murder one person is an amount the size of a grain of salt. That stuff is nasty and can be passed on in the simpliest form, and very dangerous to handle, some pretty nasty stuff.