Apothecary. At these ancient pharmacies, poison was also sold under the counter, otherwise there was a dagger
Renaissance aristocrats remained famous for the ease with which they got rid of their enemies, but how did they kill?
The "favorite" weapons were essentially two:the dagger and poison, with a certain predilection for the latter ( see https://www.pilloledistoria.it/3435/storia-moderna/luso-veleno-nel-rinascimento).
Although it was considered the weapon of the cowardly, the poison left no traces and (almost) always managed to get away with it; the use of cantarella by the Borgia, just to give an example, it has become legendary (albeit, probably, with some exaggeration).
The cantarella was nothing more than a variant of the more well-known and widespread arsenic, “ the king of poisons and the poison of kings” , at the time sold under the counter even by apothecaries (today's pharmacists).
Alternatively, as we have said, there was the dagger, in particular the stiletto, that with its thin and very sharp blade, it could be hidden without problems inside the sleeves of clothes.
The nobles, almost always even rich ones, generally did not get their hands dirty and commissioned the murders to professional hit men, who then rewarded them lavishly.
Finally, sometimes, to be on the safe side and be sure not to fail the "mission", the action of both weapons was combined by wetting the knife blades with poison, the most used of which was a preparation obtained from aconite , a highly toxic plant.