Death of serial killer Walter Ellis leaves questions unanswered

MILWAUKEE (WITI) -- A serial killer who eluded Milwaukee investigators for decades is dead. Walter Ellis died in a hospital near the South Dakota where he was serving multiple life sentences. Officials say Ellis died of natural causes.

Ellis' case involved the rapes and murders of Milwaukee women between 1986 and 2007. Some hoped he would talk more before he died.

Steven Spingola was a Milwaukee homicide detective who worked on two of the murders associated with Ellis.

"They were choked and they apparently went with him willingly up until the point the homicides occurred," said Spingola.

Ellis had been arrested twelve times for various offenses between 1981 and 1998. However, he wasn't pinned as being a serial killer until 2009. One reason Ellis got away with it at first...

"The victims were prostitutes. They had drugs in their system. They had multiple sources of DNA," said Spingola.

Ellis also eluded police because his DNA was missing from the state's data banks. It turns out Ellis got another inmate to submit DNA under Ellis' name.

Eventually Milwaukee police re-examined evidence that led them to Ellis. But that wasn't before two others, Chaunte Ott and William Avery, were convicted for two of the murders and later freed. Both are suing for wrongful convictions.

"Why he wanted to kill these women it'll go with him to his grave here. He would have been an interesting person if he would have decided to sit down like Bundy at the last minute if he knew he was dying and clear his soul, but nothing," said Spingola. "I just wonder about the other cases that he was mentioned in. There's at least five, maybe seven more that he's a good suspect in that we'll probably never know."

Ellis was serving life without parole in a South Dakota prison on a prisoner exchange program with Wisconsin. His cause of death is being investigated -- but he died at a Sioux Falls hospital. He apparently had diabetes.