How DNA Led to Arrest of South Dakota Man in 46-Year-Old Cold Case Killing of Elderly Woman

Algene Leeland Vossen
Minnehaha County Jail

Mabel Agnes Boyer Herman, 73, was found dead from multiple stab wounds at her home on Jan. 27, 1974.

Police have arrested and charged a 79-year-old man with second degree murder in the cold case stabbing of an elderly woman in 1974. 

Mabel Agnes Boyer Herman, 73, was stabbed approximately 38 times at her home in Willmar, Minnesota on Jan. 27, 1974, according to the criminal complaint filed in the case. After her sister couldn't get in touch with Herman, whom they called Mae, she went to her house and discovered her body lying on the floor and her phone ripped from the wall. 

Algene "Gene" Leeland Vossen was listed as a suspect several weeks after the killing in 1974,  the Willmar Police Department wrote on Facebook, but "evidence and interviews at that time with Vossen at that time were inconclusive." Police questioned Vossen on Feb. 19, 1974, during which he admitted to "window peeping" on several occasions after he had been released from prison, according to the complaint.

On the night of the killing, Vossen told police he was eating dinner with his girlfriend and had gone to the American Legion, according to the complaint. But his girlfriend told officers he was "an hour and a half later" to dinner than usual and he "had been drinking but was not drunk," according to the complaint.

When police questioned Vossen about the case again in 1979, according to the complaint, he was "obviously nervous and distrustful" and "was talking fast, mixing up words and visibly shaken" and wanted to know what new evidence police might have. But no arrest was made, the department said. 

It wasn't until evidence from the scene was tested for DNA decades later that investigators got a break in the case. By then, the investigation into Herman's killing by Willmar police and the Minnesota Bureau of Criminal Apprehension had spanned "several officers’ careers, multiple suspects, outside agency information, citizen tips, extensive evidence evaluation, and hundreds of pages of reports," the department wrote on Facebook. 

More than 40 years later, in June 2020, a cold case review team took up Herman's case and "discovered potential evidence on items that could be used for DNA analysis," as well as reports of a tan Chrysler registered to Vossen that had been spotted on Feb. 16, 1974 during an alleged window peeping incident. 

DNA evidence from Herman's sweater led investigators to reexamine Vossen, now 79 and living in South Dakota, police said. Police obtained a search warrant to get a DNA sample from Vossen, which matched the sample found on Herman's sweater, according to the criminal complaint. 

Vossen was arrested by police at his home in Sioux City, South Dakota on July 23 and charged with second-degree murder. He is being held in the Minnehaha County Jail in South Dakota pending extradition to Minnesota.