Did prohibition officials poison drinkers?

Moonshine itself can be poisonous, depending on the distilling process.

[T]he stills don’t stay clean after the first run. Agents have found everything from animal carcasses to beehives in the sour mash; the stillhands simply cook it all together. Worse, much of the black-pot whiskey is already dangerous stuff, high in lead content and often distilled through unflushed car radiators.