MENOMONEE FALLS, Wis. — Two cold cases that have gone unsolved for nearly 60 years have been solved thanks to DNA evidence.
The Menomonee Falls Police Department and Milwaukee Police Department have named Clarence Tappendorf as the man who killed 19-year-old Diane Olkwitz of Menomonee Falls and 15-year-old Terri Erdmann of Milwaukee.
On Wednesday morning, the Menomonee Falls Police Department hosted a press conference along with the Milwaukee Police Department, the Wisconsin Department of Justice and the FBI.
It was announced that Tappendorf’s DNA was a match to these two unsolved murders that happened decades ago.
In 1966, Olkwitz was murdered while she was at her job after work hours at Kenworth Manufacturing Company. Police said she was stabbed more than 100 times and was found by a friend who was coming to pick her up. Her case had gone cold until now.
“Clarence Tappendorf made a delivery across the street from Kenworth Manufacturing,” Menomonee Falls Police Chief Mark Waters said. “Based on the irrefutable physical evidence, it is the position of the Menomonee Falls Police Department that Clarence Tappendorf is responsible for the murder of Diane Olkwitz.”
It was just a handful of years later, in 1971, that 15-year-old Erdmann was murdered. Police said she was stabbed over 60 times after leaving a friend’s house. Her case also went cold.
“There is no statute of limitations in regards to a homicide investigation,” Milwaukee Police Chief Jeffrey Norman said. “We will work on it, whether it’s five years, ten years, or 70 years, to bring closure and a resolution to these heinous crimes.”
Over the years, police said they had about 20-30 suspects that were identified. However, it wasn’t until October 2021 that they made a break in the case. Then, a couple of months later, they found the two cases were linked.
In the summer of 2023, detectives were able to dig up Tappendorf’s body and use forensic investigative genetic genealogy to test family members' DNA. This led Tappendorf to be a match, and he is now named as the man who murdered the two girls.
Police said this type of DNA technology is relatively new, and just started using it in 2019. They mentioned that without it, this case would likely be unsolved to this day.
While Tappendorf is named as the killer for both Olkwitz and Erdmann, many may wonder if there are any more victims. Tappendorf died in 2008, and while police said they do not have any leads as of now, they will be storing this DNA to test any other unsolved similar cases during that era.
There were a few family members and friends of Olkwitz and Erdmann in attendance at Wednesday morning’s press conference. While many denied to speak on camera, they shared they were thankful these cases finally came to a close, even if it took decades to do so.
One of Olkwitz’s former classmates was in attendance and said having closure is something he never thought this community would be able to find after all these years.
“It’s just a good thing that it all has come to an end now, hopefully the family will have peace,” classmate Norman Gross said.
Police said this work was all done collaboratively and will be putting in the work to see if any other DNA is a match.