CHISHOLM, Minn. - Investigators in this Iron Range town spent more than three decades determining who didn't kill Nancy Daugherty, a well-liked aide at a local nursing home who was found strangled in her bed in the summer of 1986.
Police chief after police chief inherited the unsolved mystery. More than 100 people offered up DNA samples for comparison to what was found at the crime scene, including one that required authorities to travel to Texas to collect. Tens of thousands of dollars were offered in reward money.
But there has only ever been one arrest in the case — Michael Allan Carbo Jr., who was recently convicted of murder in the first degree while committing a sexual act.
Carbo was heading into his senior year at Chisholm High School at the time of the murder. He lived less than a mile from Daugherty then, and 34 years later remained in the same city.
"The amazing thing to the whole story is the fact that [Carbo] was able to live in that community and never say a word to anybody," said former police chief Scott Erickson. "All the publicity, all the reward money we had out there, he never said a word to anybody. What are the odds to that? Slim."
Still, Erickson, who has since moved to Washington, has no doubt that the jury convicted the right person in St. Louis County Court in mid-August, a case that still ripples through the city of 4,900 people.
More than a week after Carbo's conviction, some Chisholm residents were reluctant to talk about what has long been a cold case. Carbo has a vast network of family in town and friends in bars on the main drag who consider him kind and trustworthy. After his arrest, nearly two dozen people sent letters to the court in support of their friend, uncle, stepson. They asked for reasonable bail and promised that Carbo was not a risk to the community.
This is the only significant crime on his record.
For others, Daugherty's murder was just too long ago. Memories have faded; they were too young at the time to have followed the case.
"It was  years ago," Erickson said. "What do they know about it?"
Attempts to reach Daugherty's daughter and son were not successful.
Nancy Daugherty was preparing to move to the Twin Cities in July 1986. After years on the local ambulance crew, she had plans to attend school to become a paramedic. Her family was scattered: her recently graduated daughter in the suburbs, her son with grandparents in Grand Marais, and her husband in Germany with the 148th Fighter Wing.
Daugherty went out to a pizza parlor and bar with her friend Brian Evenson. He dropped her off after midnight, lingered for a bit and made plans to meet her in the morning to help her move some belongings into storage, according to his testimony.
But Evenson was unable to get hold of her in the morning. Daugherty didn't respond to knocks. Her doors were locked and her curtains were uncharacteristically closed. She didn't answer repeated phone calls.
Authorities found Daugherty naked in her bed beneath blankets — a single hand poking out from under the covers. She had been sexually assaulted and manually strangled. Her keys were found near matted grass in the backyard, her glasses on the floor in the kitchen.
The killer had left behind his DNA — in her body and under her fingernails. There was a fingerprint on the toilet lid.
But at the time, these clues led to dead ends rather than a suspect.
"There was frustration because it happened in Chisholm and it was a solvable case," Erickson said. "We had a small community, we had good DNA evidence. We never got any leads that went anywhere."
There was so much buzz in the community that the biweekly Chisholm Free Press/Tribune Press addressed the word-on-the-street chatter on its front page. One news story reported that there was unfounded talk of an arrest. A week later, the paper asserted that the investigation continued and the gossip about the arrest was wrong.
"All current rumors are false and the news media will carry the facts when information is released by the Chisholm police," the paper reported.
Investigators had repeatedly sought the public's help with leads — sometimes trying unconventional approaches. In 2008, Daugherty was included in a deck of 52 cold-case cards that were to be handed out in prisons, jails and correctional facilities in an attempt to jog memories of inmates and potentially solve the cases, according to news reports from the time.
Chisholm Police Chief Vern Manner contacted Parabon NanoLabs via email in early 2020. The company uses public genealogy databases to whittle down a suspect's family tree. It has been involved with bringing conclusions to 225 cold cases since 2018 — about one per week, according to Vice President Paula Armentrout.
The search narrowed to Carbo. Investigators tailed him and took a bag of garbage they watched him toss into a trash can. Inside were tissues, a beer can, Q-Tips and paper towels. They confirmed the match. It was the first time the technology has been used in Minnesota to solve a case.
Carbo maintained a low profile in the 1987 Chisholm High School yearbook. He was one of few who opted out of a senior photo. He was listed as a member of JROTC and his ambition was to join the Army. He wasn't awarded a class superlative — cutest smile, best hugger — and in a fictional letter written in the future, his classmates didn't speculate about what his life would look like. Some of his classmates were predicted to appear on "The Dating Game" or become pop stars.
Soon after the murder, Carbo and his family moved into the house next door to then-Police Chief Bob Silvestri, who was second at the scene months earlier. Now the retired chief wonders what that was like for Carbo with the near-constant presence of an unmarked squad car in front of the house.
His wife, Mary, remembered how her husband was gone for two days when Daugherty's body was found. When she finally got him on the phone, he had one thing to say: Lock the doors. The former teacher recalled using the buddy system to walk to the parking lot after school.
Silvestri didn't talk much about the case at the time, but she could see its effects on his face.
"I'm glad that in our lifetime we got to know who did it," she said.