

Introduction
Walter E. Ellis (June 24, 1960 – December 1, 2013), also known as the Milwaukee North Side Strangler, was an American serial killer who raped and strangled seven women in the city of Milwaukee, Wisconsin between 1986 and 2007.
Investigation
The North Side Strangler victims were all African-American women. Milwaukee Police Department Homicide Detective Steven Spingola authored an e-magazine article, The Killer in Our Midst: the Case of Milwaukee's North Side Strangler, which chronicled his investigation of the homicides of Sheila Farrior and Florence McCormick. Trained in criminal background analysis, Spingola provided a detailed profile of the killer, which Milwaukee talk-radio host and former Assistant U.S. Attorney Jeff Wagner described as "eerily accurate." Spingola, however, retired before Detectives Gilbert Hernandez and Kathy Hein of the Milwaukee Police Department's cold case homicide unit, reexamined DNA evidence that linked a suspect to the homicides.
On September 7, 2009, Walter E. Ellis (then aged 49), was arrested on suspicion of being the notorious serial killer. Ellis had been arrested 12 times between 1981 and 1998, when he was sentenced to five years for reckless endangerment.
Initially represented by Attorney Russell Jones in defense of these claims, Ellis pleaded not guilty, and stood prepared to defend himself. Jones was withdrawn from the case, and then on February 18, 2011, Ellis pleaded no contest to seven murders or intentional homicides, and was convicted despite not admitting his guilt. On February 24, 2011, he was given seven life sentences, to be served consecutively, without the possibility of parole. After he was convicted, he was initially held at the Dodge Correctional Institution in Waupun, Wisconsin, for Assessment and Evaluation in accordance with the Wisconsin Administrative Code, from where he was transferred to the Wisconsin Secure Program Facility in Boscobel, Wisconsin. In November 2011, Ellis was transferred to the maximum custody unit at the South Dakota State Penitentiary.
The use of the name "North Side Strangler" in reference to the case has been limited to one local news organization, WTMJ, Channel 4, which is believed to have coined the nickname, although it has been picked up by some bloggers and by British media as well. Use of the nickname, however, has also been a subject of criticism in other Milwaukee media.
Death
Ellis died at a Sioux Falls, South Dakota hospital on December 1, 2013 from apparent natural causes, according to a South Dakota Department of Corrections news release.