Erwin, Tennessee: Big Mary the Elephant

I am looking for a book in my library that has info on Big Mary, who was hung in Erwin. From what I can remember, that was her third name. The other two names I believe were "Queen" and "Empress." Her name was changed after killing one or more people and then sold to another circus. That was a very common thing, sometimes the killer Elephant was a good performer, so the show would tell the officials that it was a different elephant and they would shoot a not-so-bright one instead and the killer would carry on with a different name or be sold to another show.