Menomonee Falls cold cases linked to same man, dead for years

Two decades-old unsolved homicides in Milwaukee and Menomonee Falls are now linked to the same man who has been dead for years. 

"The Menomonee Falls Police Department has continued to work this unsolved homicide for the past 56 years.  It has always been our goal to solve this case," said Menomonee Falls Police Chief Mark Waters.

Investigators say the family of 19-year-old Diane Olkwitz has closure. In 2023, people are able to link DNA collected at the crime scene in 1966 to her killer. 

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"Det. Bellows used commercial genetic testing to locate distant relatives of the suspect," Waters said. 

"We first learned that these cases were linked in December of 2021," said Chris Bellows, Menomonee Falls Police Detective.

Diane Olkwitz, Terri Erdmann

Police say they published the killer's DNA profile in a database and it matched a sample from the 1971 Milwaukee killing of 15-year-old Terri Erdmann. Investigators then got a warrant to exhume the body of Clarence Tappendorf who died in 2008.

"It saddens me that the person responsible wasn’t able to be brought to justice while he was alive," said Josh Kaul, Wisconsin Attorney General.

Police say Tappendorf worked as a delivery driver and made a delivery to a business across the street from where Olkwitz was killed. Investigators say he was never considered a suspect. But Tappendorf's son gave police a DNA sample in May. Police say it proved Clarence Tappendorf's DNA was recovered from Olkwitz's clothing. 

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There was no answer when FOX6 News stopped by Tappendorf's son's home on Wednesday, Oct. 25. 

While officials say they have solved the case, police still do not know the motive. 

For Olkwitz's former classmate, the decades-long mystery of what happened to his friend now has closure. 

"Just going into class reunions and stuff – she’s always on your mind. This is just a tragedy that happened," said Norman Gross, former classmate of Olkwitz in 1965.

Police say Tappendorf had no known criminal record.

Olkwitz's family was at the news conference today but declined an interview. 

Investigators say they are looking into the possibility Tappendorf could be responsible for more crimes.