Woman Stabbed Over 100 Times

Diane June Olkwitz grew up in a Catholic household with her parents and five siblings in Menomonee Falls, Wisconsin. The 19-year-old worked as a secretary at a Kenworth Manufacturing Company, a metal stamping plant. She also had a part-time job as a hostess at a Dutchland Dairy restaurant.

Diane was engaged to Donald Hierlmeier who had been drafted into the army and was in Fort Hood, Texas, for basic training.

On November 3, 1966, Diane arrived at the plant around 8 AM as per usual. The factory workers’ shifts ended at 3:30 PM, however, Diane’s workday ended an hour later. During that hour, she would be at the plant by herself to answer phone calls and accept late deliveries.

After work, Diane would pick up her best friend, Diane Zimmer, as she also worked nearby. On this day, however, Diane did not show up. Zimmer was offered a ride by her employer’s wife and the two arrived at the plant around 5 PM.

Diane’s car was in the parking lot and the building’s doors were all closed. They could see through the window that Diane’s purse was on the desk and her coat near the closet. Nonetheless, there was no sign of Diane.

The two women did not know what to do so they went to a different plant nearby where Diane’s brother Dennis worked. When the three of them returned to Diane’s workplace, a supervisor had just arrived to do some after-hours work.

He unlocked the door and all four of them found Diane’s body— she was lying face down in a pool of blood, about 20 feet from the door.

Diane had been stabbed 106 times in her chest, neck, and head with a knife. About 30 of the stabs had been to her head and face, while another 35 were in rows down the sides of her back. Her cause of death was massive hemorrhaging.

Her nose was broken and she had defensive wounds on her arms and hands. Diane’s knit dress had been pulled up between her legs and was partly off her shoulders. Her undergarments were untouched. Diane had not been sexually abused.

There were no signs of forced entry. It is believed Diane was caught by surprise by her attacker as she was leaving for the day. It is likely the killer was familiar with the plant’s layout and her schedule. Moreover, Diane probably knew her killer as the way she was murdered suggests a personal issue.

Authorities investigated Diane’s murder and narrowed down six suspects, but they all had alibis. Nevertheless, police and Diane’s family have a main suspect: Diane’s employer’s son.

The person in question had made several advances towards Diane even though she was not interested. She became afraid of him because of his persistence. He was questioned extensively but authorities could not provide any evidence of his involvement. Further, he had alibis. His family corroborated that he had been with them at the time of the murder.

Given recent advancements in the use of DNA to solve cold cases, police tracked down a few of the original suspects but none of their DNA matched the evidence gathered from the crime scene.

The main suspect, the employer’s son, died in 1991. He was cremated and the whereabouts of his remains are unknown. Consequently, authorities exhumed his parents’ bodies to collect DNA but they were also not a match.

Diane’s funeral took place at St. Mary Catholic Church where she and her family were parishioners. The pastor conducting the service emplored for the killer to turn themselves in. Donald was granted emergency leave from basic training to attend the funeral. Over 250 mourners showed up.

Though heartbroken, Donald returned to the army and became a private first class. In February of 1968, he was killed by a mortar round in South Vietnam.

Diane’s family was shattered after the murder. Her mother Irene died of congestive heart failure in 1973 at the age of 50. Three years later, her father Robert died of a heart attack at age 55.

Two of Diane’s siblings have also died. The remaining three are still hoping to see their sister’s murder solved.

Diane Olkwitz’s murder has been unsolved for 53 years.