A judge has ruled that a 39-year-old murder case can move forward because a crime was committed when a four-month-old infant died in his crib.

Cumberland County Superior Court Justice Thomas Warren ruled this week that evidence that has come to light since Nathan Hagar was found dead in his crib in a Brunswick apartment on May 9, 1979 suggested the infant was likely smothered with a pillow. The death was originally attributed to Sudden Infant Death Syndrome, in which an infant dies of undetermined causes.

Burton Hagar of Farmington was charged with murder in April 2017, the first case resulting in charges as a result of a renewed investigation by the state’s unsolved murder unit.

The ruling by Warren will trigger an agreement between prosecutors and Hagar’s lawyer to have Hagar plead guilty to manslaughter and receive a 15-year-sentence. The guilty plea will be conditional, allowing Hagar to appeal Warren’s ruling to the state Supreme Judicial Court. Prosecutors had said they would appeal the ruling if it had gone the other way, so the case was destined to end up before the state’s highest court.

Hagar has confessed repeatedly over the years to smothering his son, including multiple confessions on videotape with State Police detectives. He has also confessed to four of his five wives – although not to Nathan Hagar’s mother – other relatives and counselors.

But in Maine, as in most other states, a confession is not enough. The court also has to determine that a crime was committed and, because the original ruling was that Nathan Hagar died from SIDS, police have not charged Burton Hagar during the nearly 40 years that have elapsed since the death.

The finding that a crime was committed is known as corpus delecti and is designed to keep people from being tried and sentenced based on a confession alone. As Warren noted in his ruling, some other states have adopted a less stringent federal standard that say a court has to find that confessions and other statements that imply guilt must be “trustworthy” for a case to move forward.

In April, Warren held a hearing at which a Brunswick police officer testified that he found a pillow, stained with mucus on one side, in Nathan’s crib when the officer responded to the call about an unresponsive baby on May 9, 1979. The pillow was not mentioned in the officer’s 1979 report on his response to the call.

A retired state medical examiner also told Warren that she would classify the cause of death of Nathan Hagar as asphyxiation, rather than SIDS. The medical examiner didn’t perform the autopsy on Nathan Hagar, but based her testimony on records in the case.

Warren said that, in this case, a ruling that a crime was committed can’t be resolved by medical evidence, Warren also noted that in his confessions, Hagar gave differing reasons for smothering his son – including anger at the baby’s crying, an attempt to strike back at his own father for how he was raised, jealousy and feeling trapped because of the baby.

But Warren also noted that the standard for finding that a crime has been committed is lower than for finding guilt. And he said that Brunswick Police adopted SIDS as the cause of death from the outset of their brief investigation. But the subsequent testimony that there was a pillow in the crib with mucus on the underside meets the standard of a substantial belief that Nathan Hagar was smothered. And, although Maine doesn’t use the “trustworthy” standard, Warren ruled, Hagar’s confessions were “repeated, seemingly forthright and unequivocal statements that he smothered Nathan with a pillow” would meet that standard.

Burton Hagar is led into Portland District Court in April 2018. (Shawn Patrick Ouellette/Portland Press Herald)