Investigators say new DNA testing linked Nancy Jean Trottier to the newborn found dead on a North Dakota campus in 1981.
VALLEY CITY, ND — An Arizona woman has been arrested and charged with murder in the 1981 death of a newborn girl known for decades as Baby Rebecca, a long-unsolved North Dakota case that investigators say was finally cracked through genetic genealogy and later DNA testing.
Nancy Jean Trottier, 65, was taken into custody in Sun Lakes, Arizona, and is now being held in North Dakota as prosecutors move forward with a Class AA murder case in Barnes County. The arrest matters because the infant’s death had lingered over Valley City for nearly 45 years, with generations of investigators unable to identify either the baby or a suspect. Authorities now say the case turned when advances in DNA testing let them exhume the child’s remains, build a family-tree lead and compare later samples that, in their view, tied Trottier to both the infant and biological material recovered at the scene.
The case began on April 16, 1981, when the body of a newborn girl was found in a wooded area behind Valley City State College, near 265 Viking Drive. Investigators said the infant had plastic over her face and still had her umbilical cord attached. An autopsy the next day found that she had been born alive and died from acute asphyxia, a finding authorities have long treated as consistent with suffocation. With no clear suspect and no identification for the child, police gave her the name Rebecca when she was buried. Over the years, officers chased leads that went nowhere. The case sat unresolved until 2019, when Valley City police and the North Dakota Bureau of Criminal Investigation reopened it and focused on whether newer DNA methods could do what older detective work could not.
Investigators exhumed Rebecca’s body in July 2019 and sent remains to outside laboratories for DNA extraction and genealogical analysis. By August 2020, authorities said they had received a genetic genealogy report pointing to possible relatives. That trail led them to Trottier, who had attended Valley City State College from 1978 to 1982 and had been sexually active there with the man who is now her husband, according to the probable-cause declaration. Trottier was interviewed on Oct. 12, 2021. During that interview, investigators wrote, she became emotional after learning the baby appeared connected to her family line and said, “Maybe it was me” and “It could be, maybe it was me.” Trottier agreed to provide a DNA sample, while investigators separately obtained her husband’s sample through a search warrant later that year.
The DNA results became the backbone of the charge. A forensic report received in June 2023 concluded that the most conservative estimate made it 3.481 quadrillion times more likely that Rebecca was the biological child of Trottier and her husband than an unrelated person from the general population. Investigators also said DNA consistent with Trottier was found on tissue paper recovered near the infant’s body in 1981. Another tissue paper contained a mixture matching Trottier’s DNA and DNA consistent with Rebecca, according to the declaration. Three other relatives, including Trottier’s husband, could be excluded from items collected at the scene, the document said. Prosecutors have not publicly described a motive, and the record released so far does not explain in detail what happened between the birth and the child’s death. Those gaps are likely to be central as the case moves into open court and the defense tests the strength of the state’s evidence.
For Valley City, the arrest reopened one of the town’s most painful mysteries. The baby was found on a college campus in a small community where a death like that did not fade with the next news cycle. Her grave became a local marker of a crime that had never been explained. Barnes County State’s Attorney Tonya Duffy announced the charge at a news conference Monday alongside North Dakota Attorney General Drew Wrigley and local investigators. Wrigley said the case had taken the work of many people over more than four decades. Valley City Police Lt. Dana Rustebakke credited earlier officers and police chiefs who kept the file alive even when the trail had gone cold. After the announcement, some residents went to Rebecca’s gravesite, a sign of how deeply the case had settled into local memory. Lance Peterson, a longtime Valley City resident, told local television the development brought “good closure for Valley City.”
The legal process is now moving from announcement to evidence testing. Trottier was arrested April 7 and appeared in court April 13. Judge Nicholas Thornton set bail at $2 million surety or $750,000 cash, according to local reports from the hearing. Trottier remains jailed at the Stutsman County Correctional Center in Jamestown. Her preliminary hearing and arraignment are scheduled for May 21 at 1 p.m. in Barnes County. At that stage, prosecutors are expected to lay out more of the evidence behind the charge, while the defense will get an early chance to challenge whether the case is as strong as the state says. Trottier’s lawyer, Luke Heck, disputed in court the prosecution’s description of the case as a strong one, according to reporting from the hearing. No trial date has been announced, and court records released so far do not show any additional charges beyond the Class AA murder count.
Even after the arrest, the case still carries the sadness of the original discovery. The documents describe a newborn left alone in a patch of woods, a plastic covering over her face, with signs she had lived through birth before dying. For years, Rebecca was a child known only by the name police gave her. Now investigators say they know who she was and who her parents were, but the public record still leaves many human details untold, including whether anyone else knew about the pregnancy, whether there were signs before the birth and what Trottier’s life looked like in the hours surrounding the death. Those questions may be answered only if witnesses testify or more records become public. For now, the arrest has shifted the story from mystery to prosecution, while preserving the fact that one of North Dakota’s oldest infant cold cases is no longer unsolved.
Trottier remains in custody as Barnes County prepares for the May 21 hearing, the next public step in a case that waited nearly 45 years for an arrest and now faces its first major courtroom test.
Author note: Last updated April 15, 2026.