Which preposition to use with poisoner

of Occurrences 5%

And we must remember that the poisoners of those days were very ingenious.

by Occurrences 1%

We came thither, and I was left in the hands of the landlord, who was Swiss by race, poisoner by profession, and robber by custom.

from Occurrences 1%

"And to effect the release of this poisoner from blockade.

to Occurrences 1%

Since Carmen had known him, Simeon Harp had tried his luck as a water diviner, but failing, sometimes when he most wished to succeed, in that profession, he had now definitely settled down as squirrel poisoner to the neighbourhood.

Which preposition to use with  poisoner