The letter arrived at the Henipin County Sheriff’s Office on a Thursday morning in February 1990.
It was a standard white envelope, handwritten address, no return name. Inside was a single typed page, no signature.
The tone was calm, almost formal. The way a person writes when they are trying very hard to sound like someone who has nothing to hide.
The letter claimed to be from a concerned neighbor. It offered information about the disappearance of a woman named Carol Voss.
It described a vehicle. It named a direction of travel. Every detail it contained either matched what investigators already knew or pointed carefully and deliberately toward a man who was not the person who sent the letter.
Investigators filed it. They chased the lead it offered. It went nowhere. The envelope went into the case file.
The case file went into storage. And for 33 years, nobody thought to look at the one detail the letter writer had not considered.
The postage stamp pressed to the upper right corner of the envelope, licked and sealed in the winter of 1990, containing a microscopic deposit of biological material that no amount of careful typing or deliberate misdirection could undo.
That is not a story about a letter that failed to deceive investigators. That is a story about a killer who believed he was careful enough, who sat down at a typewriter, constructed a lie, and licked a stamp, and who spent 33 years not knowing that the most precise piece of evidence in the entire investigation was the one he had pressed down with his own thumb.
And it would take three decades, a forensic genealogy team, and a Dena extraction technique that did not exist when that letter was mailed to finally pull him out of the shadow he had been standing in since 1990.
But before we get to any of that, we have to go back to Minneapolis in the winter of 1990.
Because to understand what was taken that February, you first have to understand exactly who Carol Voss was.
It was one of those Minnesota Februaries that makes no apologies. By the second week of the month in 1990, Minneapolis had buried itself under a cold that settled in somewhere around the new year and showed no intention of moving.
The kind of cold that turns the Mississippi solid at the edges. That makes your car door stick in the morning.
That turns every breath into a visible cloud the second you step outside. The city moved through it the way it always did with a particular stoic efficiency that outsiders found baffling and residents considered simply practical.
You wore the coat. You started the car 10 minutes early. You kept going. Minneapolis was a city of about 370,000 in those years, and it had the particular character of a place that has figured out how to be urban and Midwestern simultaneously.
A serious downtown, a sprawling network of lakes and parks, neighborhoods that had been built by Scandinavian and German immigrants three generations back and still carried that architecture of plainness and reliability in the way the houses sat and the streets ran.
People shoveled each other’s walks. They showed up at the potluck. They did not make a production of being decent.
They simply were. Carol Voss had lived in Minneapolis for six years when she disappeared.
Having moved from Duth at 26 after finishing her degree in social work at the University of Minnesota Duth, she had taken a position as a case manager at a family services nonprofit on Franklin Avenue.
Work that required patience, organizational precision, and the particular kind of emotional steadiness that allows a person to carry other people’s problems without being crushed by them.
Her supervisor, a man named Gerald Park, would later tell investigators that Carol was the caseworker families specifically asked to be assigned to.
That was the measure of her. He said people asked for her by name. Carol was 32 years old in the winter of 1990.
She lived in a secondf flooror apartment in the uptown neighborhood, a 7-minute walk from Lake Calhoun, which she walked around every Saturday morning, regardless of the temperature.
She drove a 1985 Volvo, the color of old pewtor that she had named without hesitation, the gray reliable, a name which suggested she had also owned unreliable things and was grateful for the contrast.
She had a younger brother named David who lived in St. Paul and met her for dinner every second Thursday.
She had a best friend named Margaret who had known her since they were both 19 years old at UMD and who described Carol in the consistent terms that only very old friends use as the most genuinely calm person she had ever met.
Not the performance of calm, but the real thing, the kind that comes from a person who has worked out what actually matters.
Carol collected transit maps, not for any practical reason she ever articulated fully. She had maps from cities she had visited and cities she had never been to, pinned to a corkboard in the hallway of her apartment, and she would sometimes stand in front of the board and trace the lines of a city she had never walked, following the roots with her finger, the way some people follow rivers on a physical map, thinking about the shape of a place through the way it moved people.
The corkboard was still on the hallway wall when investigators entered her apartment on February 17th, 1990.
The gray reliable was in its usual spot on the street below. Carol Voss was not there.
On the evening of Friday, February 16th, 1990, Carol Voss attended a small gathering at her friend Margett’s apartment in the Whittier neighborhood.
There were four people there. They ate dinner. They talked for several hours. And Carol left at approximately 10:15 p.m.
Marget watched her from the window as she walked to the corner to catch the bus.
She saw her reach the bus stop. She did not see her get on the bus.
The number 17 bus that stopped at that corner arrived at 10:22 p.m. The driver interviewed the following week did not recall a woman matching Carol’s description boarding.
The next bus arrived at 10:49 p.m. Its driver did not recall her either. David Voss called his sister’s apartment on Saturday morning.
No answer. He called again at noon. He called Margett, who had not heard from Carol since she left the previous evening.
At 2:30 p.m. On Saturday, February 17th, David Voss called the Minneapolis Police Department. The Gray Reliable was found on Sunday, February 18th, parked on a residential street in the Lynhurst neighborhood, 4 miles from the bus stop where Carol had last been seen.
It had been driven there. Carol had not driven it. Her keys were not found in the car.
Her keys were never found at all. On March 3rd, 1990, Carol Voss was found in a wooded section of Elm Creek Park Reserve in Henipin County, partially concealed beneath snowpack that had accumulated over the two weeks since her disappearance.
The Henipin County Medical Examiner confirmed homicide. She was 32 years old. The anonymous letter arrived at the sheriff’s office 4 days later.
The lead investigator assigned to Carol Voss’s case was Detective Sergeant Patricia Lundine of the Henipin County Sheriff’s Office, a 22-year veteran who had worked every category of violent crime the county produced and who had the reputation well-earned by all accounts of being the investigator who read everything, every document, every statement, every letter.
She had a rule. Nothing in a case file is trivial until proven trivial, and the only way to prove it is to read it.
She read the anonymous letter carefully. She recognized it immediately for what it was, not a genuine tip, but a constructed misdirection, a document designed to look like a neighbor’s concern and function as a distraction.
The vehicle description it offered was vague enough to apply to dozens of cars in the area.
The man it implied without naming, described only by general physical characteristics and a direction of travel, could not be identified through the letter alone.
But Patricia Lundine noted the envelope. She noted the stamp. She had it tested using the biological analysis techniques available in 1990.
Those techniques were not adequate to the task. The sample was too small. The technology not yet refined enough to produce a usable profile.
The envelope was logged, bagged, and placed in the case file. She wrote in her notes in longhand, “Letter writer knows something.
Letter writer is not a neighbor.” Envelope preserve. Two words: preserve. It was the most important instruction she ever gave in the case, and she gave it without knowing for certain what it would eventually mean.
Her investigation developed a primary suspect within the first month, a man named Walter Griggs, 38 years old, who had been a client at the Family Services nonprofit on Franklin Avenue where Carol worked.
He had been assigned to Carol’s case load for 4 months before his case was closed in November 1989.
Multiple staff members at the nonprofit described his behavior during that period as fixated and boundary violating.
He had shown up at the office after his case was closed asking for Carol by name.
He had called twice. Griggs was interviewed in March 1990 and in May 1990. He had an alibi for the evening of February 16th.
A family member who confirmed his location that Lundine found internally consistent and impossible to disprove.
His vehicle did not match any witness description. No physical evidence connected him to the Park Reserve site or to the Gray Reliable.
He was not charged. He moved to Wisconsin in 1992. Patricia Lundine retired in 2001.
She left the file with a briefing, a note attached to the evidence bag containing the envelope and stamp, and a single instruction to whoever inherited the case when the technology exists to test what is on that stamp.
Test it. By 1997, 7 years had passed. Walter Griggs was living in Green Bay.
David Voss had moved from St. Paul to Chicago for work and called the Henipin County Sheriff’s Office twice a year from an Illinois number.
Marget kept the same phone number she had always had because she wanted to be easy to reach if anyone needed to reach her.
She and David had lunch every time he came back through the Twin Cities. They talked about Carol the way people talk about someone who is still present in the room.
Present tense carefully with the slight adjustment of a person who has learned to carry absence as a kind of permanent companion.
By 2004, 14 years after Carol’s murder, the Henipin County Sheriff’s Office cold case unit submitted biological evidence from the Park Reserve site for updated Dena analysis.
The profile produced was partial but viable. It was uploaded to Cody’s. No match returned.
Walter Griggs had no prior arrests. He was not in the database. By 2011, the cold case unit had upgraded its evidence protocols.
A detective named Sergeant Roy Atkins inherited the file. He found Patricia Lundine’s note attached to the evidence bag.
He read it. He added his own note beside it, dated 2011. Technology not yet sufficient for stamp extraction.
Monitor, he monitored. Every two years, he checked whether the technology had advanced to the point where a usable Dena profile could be extracted from the adhesive layer of a licked stamp that had spent 20 plus years in a sealed evidence bag.
By 2019, 29 years after the letter arrived, it had If these cases stay with you, the detectives who write notes and attach them to evidence bags for people they will never meet.
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Now, let’s get back to Carol. In March 2022, the Henipin County Sheriff’s Cold Case Unit submitted the envelope from the anonymous letter, the full envelope with the stamp intact to the Minnesota Bureau of Criminal Apprehensions forensic biology section along with a formal request for DINA extraction from the stamps adhesive surface.
This technique by 2022 had been refined to the point where even decades old biological material deposited in the act of licking a postage stamp could yield a partial or full dena profile provided the evidence had been properly stored.
Patricia Lundine’s instruction preserve had been followed to the letter for 32 years. The extraction was completed in August 2022.
The profile was clean, complete. It was uploaded to Kodis and simultaneously submitted to a forensic genealogy laboratory in partnership with the sheriff’s office.
Walter Griggs had died in 2018 in Green Bay at the age of 66. He had never been charged with anything.
He had lived 28 years after Carol Voss’s murder in the ordinary way of a person who has not been caught.
Working, aging, becoming someone his neighbors and co-workers knew without fully knowing. The Cody’s upload returned no direct hit, but the forensic genealogy process, working outward from the Dena profile through public ancestry databases, produced a family tree that after 4 months of careful genealogical research, pointed to a single individual.
That individual was deceased. His dates matched. His geography matched. His physical description, reconstructed from family photographs and DMV records, matched what witnesses had described in 1990.
His name was Walter Griggs. He had been Patricia Lundine’s primary suspect in 1990. He had been interviewed twice and released.
He had moved to Wisconsin and lived his remaining years without consequence. The dena from the stamp of the envelope he had mailed to the Henipin County Sheriff’s Office, the letter constructed to look like a neighbor’s concern, the misdirection he had believed was clever enough to hold, matched him conclusively through genealogical confirmation and direct comparison to biological material obtained from his surviving family members, who cooperated fully with investigators.
He had licked the stamp. In February 1990, on a winter evening in Minneapolis, he had sat down and constructed a careful lie and licked a stamp to seal it shut.
And the stamp had kept what he left on it for 33 years. Patient as evidence always is, waiting in an evidence bag in a building in Henipin County for the technology and the person and the moment to arrive.
The Henipin County Sheriff’s Office issued a formal statement in January 2023, naming Walter Griggs as the perpetrator in the murder of Carol Voss.
Because Griggs had died in 2018, no criminal charges could be filed and no trial would take place.
The statement confirmed that the Dena evidence combined with the circumstantial record developed by Detective Sergeant Patricia Lundine in 1990 would have supported a first-degree murder conviction had Griggs been alive to face it.
David Voss was in Chicago when the call came. He drove to Minneapolis that same day.
He went to Marget’s apartment, which she still had, and they sat together in the living room that Carol had never been to, but which somehow still felt to both of them like somewhere she should have been.
Marget made coffee. They talked for 4 hours. David gave a brief statement to the press the following week.
He said, “Carol kept transit maps on her wall. She would trace the roots of cities she had never visited, thinking about the shape of a place through the way it moved.
She was 32 years old and she was still figuring out what shape her own life was going to take.
Somebody ended that and then he sat down and typed a letter and thought that would be enough to keep himself safe.
He underestimated what she left behind. Patricia Lundine, retired and living in Duth, was contacted by the Henipin County Sheriff’s Office the day before the public announcement.
She was 83 years old. She had kept a copy of her own case notes, the originals, in a filing cabinet in her study.
When the detective who called her described how the case had closed, the stamp, the genealogy, the profile, she was quiet for a moment and then said, “I knew it was in that envelope.
I could not get to it, but I knew it was there.” She had known for 33 years.
There is something that the best investigators understand about evidence that the rest of us only appreciate in retrospect.
Evidence does not expire. It does not grow impatient. It does not decide after a decade or two that it has waited long enough and let go of what it holds.
A stamp on an envelope in a sealed evidence bag in a county property room holds exactly what it held on the day it was licked.
Through every season and every budget cycle and every personnel change and every year the family calls and the case stays open.
What changes is the human capacity to read it. The technology gets better. The genealogy databases grow larger.
The extraction techniques become more refined. And at some point, not always, but sometimes, the distance between what the evidence holds and what investigators can extract from it closes completely.
That is what happened in the Carol Voss case. Not luck, not a break. The convergence of patience and technology across 33 years around a piece of biological material that Walter Griggs deposited on a winter evening in 1990 without understanding what he was doing.
He thought he was sealing a letter. He was leaving a confession. Carol Voss was 32 years old.
She walked around Lake Calhoun every Saturday morning in the Minnesota winter because she found it worth doing.
She kept transit maps on her wall and traced the roots of cities she had never visited.
She was the case worker that families asked for by name. She made coffee with Marget and had dinner with David and drove the Gray Reliable to the places she needed to go.
She deserved to keep going. She deserved every city on that corkboard, every route she had not yet walked.
Remember her name. If this story stayed with you, leave a comment below. Did Patricia Lundine’s 1990 instinct about that envelope change how you think about what investigators do in the first days of a case?
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