South Dakota man arrested in 46-year-old Willmar homicide case

A South Dakota man was arrested Thursday in connection to a 1974 homicide case in Willmar.

Willmar Police said 79-year-old Algene Leeland Vossen, of Sioux Falls, S.D., was arrested for the murder of Mabel "Mae" Agnes Boyer Herman in 1974. Vossen is being held in the Minnehaha County Jail pending extradition to Minnesota.

The department said police were called to a home in the 800 block of Sixth Street SW at about 8:43 p.m. on Jan. 27, 1974. Police said family members had gone to check on an elderly relative who wasn’t answering her phone. When officers arrived, they found Herman, 74, dead from what appeared to be multiple stab wounds.

Evidence evaluation at the time was inconclusive, police said.

In June of 2020, Willmar Police created a temporary cold case review team to look at unsolved cases, including Herman’s homicide.

The review found that Vossen had been listed as a suspect initially but the evidence was inconclusive. Officers reviewing the case determined he was a significant suspect again.

Officers also discovered potential evidence on items that had been preserved that could be used for DNA analysis. The evidence was sent to the Minnesota Bureau of Criminal Apprehension (BCA) where it was examined by a forensic scientist. The DNA was compared to various suspects but didn’t match. Vossen’s DNA, however, wasn’t in any database for comparison.

Police said the officers reviewing the case learned Vossen was living in Sioux Falls, and with assistance from the South Dakota Division of Criminal Investigation, a search warrant was obtained for a DNA sample from Vossen. The DNA sample was then sent to the BCA Crime Lab were evidence from the case matched Vossen’s DNA.

An arrest warrant for second-degree murder was obtained on Thursday and Vossen was placed under arrest by the South Dakota Division of Criminal Investigations, Sioux Falls Police and Willmar Police.

The department credited the considerable work done by many officers over decades for carefully collecting, packaging and preserving the evidence, and newer technology for connecting Vossen to the homicide.