Charges dismissed in central Minnesota cold case homicide after death of defendant

Algene Vossen, 81, who was arrested in Sioux Falls, had previously been found incompetent to stand trial for the 1974 killing of Mae Herman in her Willmar home.

Case reports dating back to the mid 1970s were read by the Willmar Police Department Cold Case Review Team that identified a suspect in the 1974 killing of Mabel "Mae" Agnes Boyer Herman. Algene Leeland Vossen was charged in 2020. Vossen died a week ago, and the case has been dismissed.
Erica Dischino / West Central Tribune file photo

WILLMAR, Minn. — The 81-year-old former Willmar man charged with murder in a 1974 stabbing death has died.

Algene Leeland Vossen was charged in 2020 with second-degree murder after a cold case homicide investigation into the killing of Mae Herman in her Willmar home identified him as a suspect. The criminal case has now been dismissed.

First Assistant Kandiyohi County Attorney Kristen Pierce notified the court Monday, May 22.

Vossen had been a patient at Unity Point Hospital in Des Moines, Iowa, and under 24-hour electronic monitoring by caretakers and staff since June of 2022. According to court documents, Vossen died there on the night of May 15.

Algene Leeland Vossen
Contributed / Minnehaha County (S.D.) Jail

The Kandiyohi County Attorney’s Office filed a petition in August 2022 to have Vossen committed as mentally ill and dangerous. In that separate civil commitment proceeding, Kandiyohi County District Judge Wentzell in February had ordered a six-month commitment , concluding that Vossen was mentally ill.


Vossen had previously been found incompetent to stand trial in the Kandiyohi County District Court criminal case. According to court documents in the criminal case, another competency evaluation was to be filed no later than July 28, and Vossen's next scheduled hearing had been slated for June 8.

In the court ruling that committed Vossen as mentally ill, the judge noted that Vossen was barely ambulatory at the time of the ruling.

In the Nov. 5, 2021, ruling that found Vossen incompetent to proceed in the criminal case, Judge Wentzell cited testimony from three evaluators suggesting that Vossen suffered from, "significant memory impairment, specifically regarding newly learned information." The County Attorney's office appealed the decision, which was ultimately upheld by the Minnesota Court of Appeals. The Minnesota Supreme Court declined to review the lower courts' rulings.

Vossen's condition worsened over time. Testimony at a Nov. 18, 2022, hearing regarding Vossen's commitment included statements from medical professionals who said Vossen suffered from dementia and a major depressive disorder. The conditions contributed to Vossen's impaired judgment, behavior and capacity to recognize reality, according to a Pierce's filing. All of this, along with aggressive acts, also made it difficult to place Vossen in secure facility willing to accept him.

Mabel "Mae" Herman was found dead in her Willmar home on Jan. 27, 1974. Her body was found lying on the floor fully clothed. She had 38 stab wounds to her neck, chest and left torso.

The homicide occurred around a period of time when Vossen, a Willmar native, admitted he was window peeping in Willmar. He denied killing Herman and told investigators that he did not know her and was never in her home. Evidence against him was inconclusive at the time.

Vossen was arrested in 2020 after investigators of the cold case identified evidence that could be used for DNA analysis.

According to West Central Tribune archives, a state crime lab indicated DNA collected from evidence in the homicide matched Vossen's. DNA in a bloodspot on the arm of the sweater had ruled out two other suspects in Herman's death but had matched with the sample taken from Vossen.


Vossen was arrested and charged at what then was his Sioux Falls, South Dakota, home on July 23, 2020.

Dale Morin is a reporter with the West Central Tribune. He covers public safety and breaking news beats.

Dale can be reached at or by phone 320-214-4368.
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