Criminal complaint details events leading to Vossen's arrest in Willmar cold case homicide

A 46-year-old cold case finally has a suspect in custody after law enforcement was able to match DNA from Algene Leeland Vossen, 79, of Sioux Falls, South Dakota, to the 1974 stabbing death of Mabel Agnes Boyer Herman in her home in Willmar.

Algene Leeland Vossen Photo via Minnehaha County (S.D.) Jail
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WILLMAR — After 46 years, a suspect has been arrested in the death of Mabel (Mae) Agnes Boyer Herman on a cold January day in Willmar.

Algene Leeland Vossen, 79, of Sioux Falls, South Dakota, formerly of Willmar, was arrested Thursday at his home in Sioux Falls. He is awaiting extradition to Minnesota to face a charge of second-degree murder.

According to the warrant complaint for Vossen filed in Kandiyohi County District Court, Herman, aged 73, was found dead in her home on the evening of Jan. 27, 1974, after being stabbed approximately 38 times.

Any homicide would trouble people in Willmar, even today, but an elderly woman being so brutally killed in her home sent shock waves through the city.


“It wasn’t a personal fear that some guy was going to jump out of the bushes and stab me,” said Brad Koenig, 65, who went to Ridgewater College at the time. “Because it was an elderly woman, I think it was more disgust and shock that something like this could happen in Willmar.”

Investigators noted that no money appeared to have been stolen or other property taken from the home, nor did anything in the house appear to be disturbed but her phone had been ripped out. A newspaper dated the previous day, Jan. 26, 1974, was in the living room and appeared to have been read.

No weapon was found.

Koenig, who currently lives in Hector, said he had recently been talking about the case with his brother.

“It’s just awful,” Koenig said. “(Our response was) just kind of a universal ‘I hope they catch him.’”

Vossen became a person of interest during the initial investigation, being first interviewed by investigators on Feb. 19, 1974, according to the complaint.

Vossen was known to local law enforcement and had served a stint in Stillwater prison.


"(Vossen) was a bum," said Mike Gunter, 72, former West Central Tribune photographer. Gunter was also the primary crime scene photographer for the Willmar Police Department at the time.

"He'd been into a lot of trouble, petty thefts, et cetera," said Gunter.

Vossen had been stopped on Feb. 16, 1974, for a window peeping incident when he had told officers he picks his houses at random and had no special desire for older women.

During the initial interview, Vossen said that since his release from Stillwater prison in May of 1973, he had been window peeping on multiple occasions. Vossen admitted he needed mental help, according to the narrative in the complaint.

Vossen told investigators during the interview that he did not know Herman and didn't know anything about the case other than town talk and what was said in the newspaper and on the radio.

Vossen said he had been bar hopping in Willmar the nights of Jan. 26 and Jan. 27 in 1974 and that he and his then-girlfriend, Lydia Olson, usually went to John's Supper Club and then the Veterans of Foreign Wars post and/or the American Legion in Willmar.

"I know they interrogated him pretty heavily," Gunter said. "They really thought that he was probably the culprit, but I just don't think they had enough evidence that they could put the last nail on the board."

Olson, who did clerical work at the West Central Tribune at the time, told an investigator on May 20, 1974, that Vossen came home around 9 p.m. Jan. 26, about an hour and half later than he usually came home, as they always had supper at 7:30 p.m.


She said that Vossen had been drinking but was not drunk.

Vossen and Olson would later marry in October 1974 in Iowa. She died in May of this year in Sioux Falls. Her obituary states they lived in Iowa before moving to Sioux Falls in 1993.

The investigation

Willmar’s Police Chief at the time, Lyle Goeddertz, told the newspaper in April of 1974 the investigation had hit a brick wall.

Glenn Negen, 73, had been on the Willmar police force for just six months when Herman's body was found.

Negen said he played a minor role in the investigation, mainly guarding the Herman house so police didn't have to get another search warrant, but that there was some urgency within the department to catch the killer.

"The concern was the unknown part: Do we have a murderer in our our presence and is he going to do it again?" Negen said.

On Dec. 21, 1979, an investigator traveled to Des Moines, Iowa, to meet with Vossen at a Denny's restaurant.

According to the complaint, Vossen immediately wanted to know what was going on and was "obviously nervous and distrustful (of the investigator)."

The investigator indicated he was not going to arrest Vossen but wanted to talk with him about the homicide, mentioning that the department had a psychologist who was interviewing witnesses and suspects in the case.

Vossen declined to travel to Willmar from Iowa for an interview with the psychologist, citing work obligations.

According to the complaint, Vossen told the investigator "there was no way in hell that he was going to Minnesota or was going to talk further about the case" and that police would need to get a warrant for his arrest if they wanted to talk with him further.

Vossen then wanted to know about any evidence in the case that made the officer travel to Iowa to speak with him. The investigator declined to discuss details, saying it would be "bad police work" to do so.

The investigator noted that Vossen was "quite excited" during the interview, talking fast, visibly shaken and mixing up his words.

The investigator also noted that Vossen's main concern seemed to be what new evidence the police had uncovered in the murder investigation regarding him, according to the complaint.

Cold case

In June 2020, the Willmar Police Department, now headed by Police Chief Jim Felt, set up a temporary cold case review team that took another look at the Herman homicide, as well as other cold cases.

During the investigation, they found that Vossen had previously been listed as a suspect in 1974, and he soon became a significant suspect again. DNA evidence they found at the scene did not come back as a match for any other known suspects or those in the database.

Vossen’s DNA was not in any database or in evidence.

Vossen was in Sioux Falls, South Dakota, and a search warrant was obtained for Vossen’s DNA on July 7, 2020.

While officers obtained Vossen's DNA, Vossen told them that he did not know Herman and had not been at her house.

He said the night she was killed, he was at the American Legion and that there was no reason why his DNA would be found on Herman's clothing. He said he had no concerns with blood coming back as his DNA.

On July 17, that sample police obtained from Vossen came back as a match for the 1974 homicide.

"When the department got the results of a match from the evidence to a suspect in the homicide, we were elated," Felt wrote via email. "Our constant thoughts were to try and get some answers to the Herman family, to be able to clear people who had long been considered suspects although innocent, and to hold the suspect accountable. These results helped accomplish all of those things."

On Thursday, officers from the Willmar Police Department obtained a warrant for Vossen’s arrest on second-degree murder.

Vossen was arrested without incident at his home in Sioux Falls by the South Dakota Division of Criminal Investigation, the Sioux Falls Police Department and officers from the Willmar Police Department.

When Negen heard the news that Vossen was arrested, he said he was ecstatic.

"It was exhilarating," Negen said. "Really, really happy to hear."

Vossen is currently being held in the Minnehaha County, South Dakota, jail pending extradition proceedings.

Mabel "Mae" Agnes Boyer Herman's body is removed from her home at 804 West Sixth Street by Willmar police officers Sanford Larson and Roger Klinghagen. She was found dead on Jan. 27, 1974. Willmar police have made an arrest in the homicide that had remained unsolved for 46 years. Mike Gunter / West Central Tribune file photo

Mark Wasson has been a public safety reporter with Post Bulletin since May 2022. Previously, he worked as a general assignment reporter in the southwest metro and as a public safety reporter in Willmar, Minn. Readers can reach Mark at
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