Well, these people all turned to some form of medicine to use as a poison.

Although less common, it can be used as a poison for vertebrates, such as rabbits.

White hellebore is an herb that was used historically in Rome as a poison.

The species is well known in Central America, where its poisonous sap has been used both as a medicine and a poison.

All parts of this plant are extremely toxic, and it has historically been used as a poison on arrows.

It is used in folk medicine as a poison, antiseptic, and a purgative.

It is also used as a poison in slug baits.

My guess is he must have seen the medicine cabinet through the open bathroom door and went in looking for something to use as a poison.

The sap has long been used as a poison and powerful purgative, noted in early medical texts.