SOLVED: Mary Schlais: Justice at Last
I’ve always been a big fan of genealogy.
Genealogy, the study of family history, has been a popular discipline and hobby for many people for decades.
After I graduated from college, I took my first real steps into researching my own family tree. At first, it was a mixture of curiosity and wanting to hone my historical research skills that got me into it. It didn’t take long for it to become something more.
Internet genealogy was still in its infancy, which meant if you really wanted to get into it, you had to go to libraries and courthouses in person to pour through old books, vital records, and sift through endless reels of microfilm.
To be clear, this isn’t some silly story about how we did the equivalent of walk five miles to school every day but Sunday through snow drifts and pouring rain back then. We did it because we had to.
Twenty years ago or so, it was the only way to get the information that we needed. Honestly, I was ecstatic when the online genealogical databases started becoming the powerhouses that they are today. I could sit in my office at home and look through all the same data with zero drive time. I was looking through information on my ancestors who died half a country away from the comfort of my favorite chair.
However, those technological innovations made genealogy more convenient, not easier.
The science – the discipline – hadn’t changed at all.
I still spent hours looking through records and would still get just as frustrated when I couldn’t find something as I had before. You still had to compile all your information correctly, verify your claims, and cite your sources so that others can find the same information that you did.
As technology gets better and the scientific knowledge of the human race expands, the advances keep coming.
In the last decade or so, geneticists, professional genealogists, and law enforcement officials have combined their knowledge to pioneer a new discipline – forensic genealogy. This new field is allowing authorities to trace the history of DNA samples and build up a pool of suspects in cases that have been cold for years.
Just a few weeks ago at the time that I’m compiling this episode, forensic genealogy was instrumental in cracking the case of Mary Schlais, a woman who was brutally murdered and left in a ditch over fifty years ago.
Honestly, I never thought that it would be solved. I thought that, like so many other cold cases out there, it would fade away and that Mary would never get justice.
Thanks to the incredible efforts of the Dunn County, Wisconsin Sheriff’s Department and their unwillingness to abandon the case even five decades later, I’m very happy to say that I was wrong.
The story that follows is the incredible story of all of the people that never gave up hope and assisted in solving one of Wisconsin’s oldest cold cases.
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Dunn County, Wisconsin, 1974
Dennis Anderson thought it was a good day for a drive. He let his mind wander as he drove along the rural Wisconsin back roads. There was no stress, no urgency to go somewhere or get something done. It was just him, his car, and the open road. Oh, and his dog.
He glanced over at the passenger seat. His dog was looking out the window, watching the scenery pass by. He smiled. His dog seemed to be enjoying the ride just as much as he was.
Earlier that day, they had gone to take care of some shopping. When they had finished and they had started to head for home, Dennis realized that he didn’t feel like going back home yet. There was something so peaceful, so relaxing about driving that he decided to just keep doing it.
Before long, Anderson found himself turning down a dead-end road. Up ahead he could see a gold-colored compact car parked along the side of the road. A man was pulling something out of the passenger side.
As Dennis drove past, he made eye contact with the driver. The look on their face was a strange mixture of surprise and anger. Dennis turned his gaze away and kept driving down the road.
There was something about that scene that didn’t sit right with him. The more he thought about it, something about the whole thing seemed wrong.
The more he rolled it over in his mind, the more it bothered him. He didn’t know what, but there was something telling him there was something very wrong about the situation. Slowing the car, he turned around and began to drive back.
By the time he got there, the car was gone, but he could still make out tire tracks in the snow. He could also see what the driver had been pulling out of the vehicle – a body. Whoever was lying there, they weren’t moving.
Anderson hit the accelerator and sped home to get help.
When he got there, he ran inside and quickly told his wife what he had seen, then got his neighbor to come back with him to help the person in the ditch.
When they returned, the person was still there. As they came closer, the men could see that it was a young woman and that she was covered in blood. Sadly, she was already dead.
The two men returned to their car and went to a nearby home to call the sheriff’s department.
When the police arrived, they were able to identify the woman as Mary Schlais from Minneapolis, Minnesota.
Tire tracks were found in the snow, presumedly from the car that Anderson had seen earlier. Crime scene technicians carefully took photographs and measurements of the tire treads, but the snow didn’t allow the plaster mold to set right, and they were ultimately unusable.
An autopsy of Mary’s body revealed that she had been badly beaten. Her nose had been broken, and she had several bruises all over her body and face. She had been stabbed 15 times in her neck, back, and stomach by a thin-bladed knife.
Mary had fought back hard against her attacker. There were several cuts on her hands, defensive wounds received while trying to ward off her killer. Mary had also scratched her killer in the fight, and blood and skin samples were removed from under her fingernails and preserved.
Most importantly, an orange and black stocking cap were found at the scene. Just remember that for now. We’ll get back to it.
They learned that Mary Kathleen Schlais was born in Minneapolis, Minnesota, on Nov. 4, 1948.
Mary was an extremely intelligent, beautiful young woman. Mary graduated with honors from the University of Minnesota in 1973 and had started working toward her masters degree. She spoke three languages – Dutch, German, and English – fluently, and had just started to learn Japanese.
She loved to travel and had been all over the United States and Europe. Most of that had been done hitchhiking.
I know, I know – Never hitchhike! Like me, most of you probably grew up being told never to hitchhike.
But this was the late 1960’s and early 1970’s, man. Hitchhiking was a thing that a lot of people did, and it was perfectly acceptable. Well, mostly.
Most people were at least slightly aware of the dangers of hitchhiking by then. Stories were told and retold of people who had hitched a ride with the wrong person, and they ended up dead.
Personally, I have very little doubt that an intelligent person like Mary had heard these stories, but she was young and brave and carefree. She had done it lots of times and nothing had ever happened to her. She had travelled all over the United States hitching rides from place to place, and when she went to Europe, she got around the same way.
So, when there was an art show in Chicago that Mary wanted to see in early 1974, she didn’t hesitate. She knew exactly how she was going to get there.
Her plan was to hitchhike from Minneapolis to Madison, Wisconsin, then make her way down to Chicago. At around 10:30 am on February 15, 1974, Mary Schlais said goodbye to her roommate and headed out the door to find her first ride.
Just under three hours and 90 miles later, Mary was found stabbed to death in Dunn County.
Police followed up on every lead and suspect that they possibly could. Around 100 formal interviews were made, with far more informal ones.
The only witness to any part of the crime was Dennis Anderson, and he helped however he could. The police questioned him extensively, then had him look at several photo line-ups, none of which yielded any results. They even hypnotized him not once, but twice, to maybe see if there was some hidden detail buried in his subconscious. Unfortunately, those efforts also led to nothing.
With no suspects and no hard evidence at the crime scene to link to the killer, the case quickly went cold. There was nothing else for the police to do. But that didn’t mean that they gave up hope.
Over the years, they diligently followed up on any new clue that might crack the case, but nothing led them to Mary’s killer.
Little did they know it then, but new scientific breakthroughs were being developed that would crack the case wide open, and they had the key sitting in an evidence locker.
DNA first pushed itself into the forefront of scientific knowledge in 1953. It would take another thirty-three years before it was used for the first time in a criminal case in the United States.
The use of DNA evidence continued to grow and expand its role in forensic science until it became one of the most important tools available to modern criminal investigators.
Detectives in Dunn County, still unwilling to give up on catching Mary Schlais’ killer, became very interested.
According to people who know science stuff way better than I do, about 99.9 percent of DNA from person to person is the same. But that amazing 0.1 percent is where the magic happens. In that tiny amount, there can be millions of possible combinations that are unique to each person, just like fingerprints.
For our purposes here, that means if someone leaves some kind of DNA behind at the scene of a crime – bodily fluids, skin, etc. – then that sample can be matched, also like a fingerprint, to any possible suspects. If it’s a match, then that means that person was almost definitely at the place where the sample was taken from.
To start the process, investigators need a sample of DNA from the suspect. Luckily, Dunn County had it.
Remember that stocking cap found at the crime scene in 1974? It contained numerous hairs, presumably from the killer. That hair gave Dunn County detectives the sample that they needed. Maybe, they hoped, just maybe, this evidence would help them solve the case.
Using the hairs, scientists were able to construct a partial DNA profile of the stocking cap owner. They immediately compared their partial profile against CODIS. CODIS, or Combined DNA Index System, is a database of DNA profiles taken from criminals that was established in the United States by the Federal Bureau of Investigation.
Unfortunately, the partial profile didn’t match anything in the database, meaning that Mary’s killer’s DNA had never been entered into the system.
The samples were returned to storage and the detectives settled back in to wait for their next opportunity.
Over the next several years, DNA databases were established all over the world, with some of them being publicly accessible. Some companies that specialized in helping people with their genealogy began to offer use of these databases to help people find out where their families were from.
All you had to do is buy one of their ancestry kits for roughly $100 (prices vary), provide a sample of spit, then send it into the company. Scientists compiled your genetic profile then compared your DNA against the database.
People began sending their DNA in the hopes of uncovering new leads in their own quests to fill out their family tree. Before long, the databases were full of countless people from all over the world. In a relatively short amount of time, these databases were full of genetic data from people exploring their family history.
At some point, law enforcement, geneticists, and professional genealogists saw another opportunity to utilize these databases. Someone realized that many of the samples in these private databases weren’t in the law enforcement databases like CODIS. However, there were a lot of criminals in the world who had never been caught, meaning that a DNA match could be in one of these private databases.
From that theory, forensic genealogy was born.
Time and time again, it has helped identify victims and bring new suspects to light in cold cases. Perhaps the most famous instance of this was the case of the Golden State Killer in California.
The Golden State Killer was a rapist and serial killer who terrorized the citizens of California for decades. Despite the best efforts of police, he eluded capture time and time again as the number of his victims continued to grow.
From one of the crime scenes, police had obtained an unidentified genetic sample that had come from the attacker.
There was a chance that there could be a match in one of the public DNA databases. After persuading one company to allow them access, they used a sample of DNA from the Golden State Killer, compared it to existing samples in the database, and eventually got their match, a man named Joseph DeAngelo.
Wow! Sounds so simple, doesn’t it? Unfortunately, not quite.
The first step is to have a sample from a potential suspect. That sample is then entered into with a law enforcement database like CODIS. If there’s no match, then they enter it into a private database such as GEDmatch.
Any close matches to the sample are recorded on a list, with each similar match types separated into groups. For each match in those groups, investigators build a family tree, filling out each branch until they find a common ancestral couple for the samples.
Investigators then work forward in time, following the descendants of that couple. These individuals are then filtered out until a list of viable candidates is left, which is presented back to detectives to follow up on.
In late 2022, the Dunn County Sheriff’s Department was approached by the Investigative Genetic Genealogy Center, or IGG Center, at Ramapo College in New Jersey, which specializes in the use of forensic genealogy.
Detectives were glad to have their help and began discussing the case with them. By the spring of 2023 the IGG Center, working with the Wisconsin State Crime Lab, officially began working on the Mary Schlais case.
Over the next several months, a possible family tree of a possible suspect was assembled using the hairs from the stocking cap. By January 2024, the search was narrowed down to one suspect.
It was at this point in the case that traditional detective work took over and detectives began to look into their new suspect.
By May, careful questioning, investigation, and further DNA comparison determined that the individual had not been involved with the murder.
However, the IGG determined that their first cousin could be the contributor of the DNA at the crime scene instead. Unfortunately, a DNA sample provided by them was not a match to the killer, either.
With this last suspect ruled out, there were no other male suspects in the genetic line being investigated. The investigators knew that their DNA profile was close to the killer, but if everyone had been ruled out, then who could it be?
As they worked on the question, someone came up with the idea that maybe the killer had been adopted from that family. It would give a match to the DNA profile but still have nothing to do with their original family.
With that in mind, IGG began to investigate the theory.
On November 4, 2024, on what would have been Mary’s 76th birthday, the IGG confirmed a new match and gave police a new suspect. Three day later, detectives visited the home of an 84-year-old man named Jon Keith Miller in Minnesota.
As soon as he opened the door, Miller later stated that he knew exactly why the police were there. He soon confessed to having murdered Mary Schlais in 1974.
According to the story he gave detectives, he had seen Mary hitchhiking and had picked her up. As they drove, he began to ask her for sex. She wasn’t interested and told him no. When she did, Miller grabbed a knife that he kept in the car and used it to stab Mary to death.
Miller then drove to a remote road so he could hide her body in a snowbank. As he was doing so, he saw a car drive by. Scared that they had seen what he was doing and were going to get the authorities, he dropped her body in the ditch and drove away.
What was just as important was that Miller confirmed that the stocking cap found at the scene – the one that the DNA sample had been taken from – had been his.
The story had come full circle and, after 50 years, Mary Schlais’ killer had finally been found.
Miller was arrested and is now being housed in the Dunn County Jail in Wisconsin. As of the publication of this episode, he had made his first court appearance.
This is a story that I never expected to tell. It’s a story of unrelenting hope in the face of an impossible task, and a crime that I never expected to be solved has finally come to an end.
Sources
Bettin, Anthony. How DNA helped find alleged killer in 1974 Wisconsin cold case. Cbsnews.com, 11/11/2024
History of CPR. American Heart Association. Cpr.heart.org.
Bygd, Sheriff Kevin. Dunn County Sheriff Investigators Solve Cold Case 1974 Murder of Mary Schlais. Dunncountysheriff.com
O’Brien, Christena T. Cold murder case not forgotten. Leader-Telegram, 6/29/2003.
Mary Kathleen Schlais. Find a Grave.com
What is DNA profiling? Yourgenome.org
Wilson, Lauren. History and Overview of Forensic DNA. Encyclopedia of Forensic Sciences, Third Edition, 2023. Sciencedirect.com
McDermott, Marc. Investigative Genetic Genealogy: How Does it Work? Ishinews.com
Tucker, Emma. A woman was murdered in 1974 while hitchhiking to a Chicago art show. 50 years later, investigators found her killer. cnn.com
Investigative Genetic Genealogy Center. Ramapo.edu
Officials, family of Mary Schlais speak on charges in 1974 Wis. Cold case killing/ Live coverage. WCCO – CBS Minnesota. Youtube.com.
Genealogy team explains how they helped solve 50-year old case. KARE 11. Youtube.com