SIOUX FALLS, S.D. (KELO) — A cold case investigation involving a Sioux Falls man is not over.

Last November, KELOLAND Investigates reported a judge ruled that Algene Vossen, 80, was mentally incompetent to stand trial for the murder of a Willmar, Minnesota, woman back in 1974.

Prosecutors immediately filed an appeal and Thursday, April 14, presented their arguments in front of a judge.

Now KELOLAND Investigates has learned there may be more to this story, a lot more.

Algene Vossen is accused of killing Mable Herman of Willmar, Minnesota, almost 50 years ago.

Vossen, who lived in Willmar at the time, was immediately a person of interest and questioned in the case. New DNA testing tied him to the murder, according to law enforcement.

Back in November a judge ruled, after hearing from mental health experts, that Vossen was determined to be mentally unfit to stand trial.

They pointed out that Vossen is suffering from significant memory loss.

His attorney Kent Marshall argued some of those same points yesterday in front of the Minnesota Court of Appeals.

“I don’t think it’s a strong appeal for the state for a couple of reasons, the trial court heard from three different experts two of whom thought Mr. Vossen wasn’t competent to proceed, the state hired an expert who had a different opinion and I think the trial court made real specific findings that will be upheld on appeal,” Marshall said.

Vossen was arrested at his Sioux Falls home two years ago after the Willmar Police Department found new DNA evidence allegedly tying him to the murder.

But KELOLAND Investigates has learned Vossen is being looked at for two cold cases in Iowa.

In 1976, 80-year-old Emma Lewis was found dead in her Waukee, Iowa, home. Police say she died from blows during a severe beating.

In 1978, 57-year-old Anna Miller was discovered dead in her Des Moines, Iowa, home. The county examiner determined she died from blunt force trauma to the head, the weapon was likely an axe.

Don: Was Mr. Vossen in that area of Waukee, Iowa, back in 1976 or Des Moines in 1978?
Kent: He may have been.
Don: You don’t know for sure?
Kent: I know that they were looking at him as a person of interest in one of those cases during that time frame, so it’s my assumption he was.

Vossen’s attorney says Vossen was a person of interest back then, but authorities didn’t have the evidence to charge him, so they never pursued it any further.

But Iowa authorities have recently reached out to the Willmar police Department.

The chief of police, Jim Felt, tells KELOLAND Investigates via email.

“Our agency has provided investigative records and DNA analysis to those agencies to assist in their investigations. While it’s unknown if Vossen was involved, it often is the sharing of information and cooperative efforts that can lead to resolution of these cases.”

Vossen’s attorney says he’s aware of the Iowa investigations.

“I suspect they’ll simply run the DNA analysis with respect to both of them, again I don’t think it’s unusual to grab DNA from someone who is accused in another jurisdiction and to see if they match up,” Marshall said.

KELOLAND Investigates reached out to investigators in Iowa for comment, but they never returned our calls.

We also reached out to prosecutors in Minnesota, but again we never heard back.

KELOLAND Investigates will continue following this case and keep you updated as we get new developments.