How many psycho killers from Wisconsin?

Wisconsin has most likely incurred a bad reputation for breeding "psycho killers" because not merely one, but three serial killers (two of whom cannibalized their victims) hail from there. Firstly, there is the infamous Ed Gein, from PLainfeild, WI. Second, there's Jeffrey Dahmer, from Milwaukee, WI, as well as David Spanbauer from Kempster, WI. And that's not to mention all the weird happenings in Black River Falls, WI that are documented in the book Wisconsin Death Trip.

Another one got added to the list Walter Ellis from Franklin. He went on a 21 year killing spree. Killing 9 women, 8 were prostitutes and 1 was a runaway doing a drug trade. So far that is four.