Good question! You can definitely look at these characters and see that they've got a history.
We didn't actually write back stories for the characters, although we did assume that even each of the Puritans has some skeletons in their closet. I think they have used witchcraft as an excuse to flee Salem, but each has their own selfish motives (which are supported by the scoring mechanics).
If anyone wants to get creative and suggest some back stories, go right ahead. We'd like to do am expansion in the future if there's enough interest; maybe we'll write some back stories to include with the expansion.
Heck, from what it seems, some might actually BE witches...