PORTLAND (NEWS CENTER Maine) - A man accused of killing his four-month-old child in Brunswick back in 1979, was back before a judge Tuesday.

Burton Hagar is charged with murder, in a case that was originally ruled Sudden Infant Death Syndrome. But in the years since Nathan Hagar’s death, police say his father admitted to several people he smothered the baby with a pillow. Last year a grand jury indicted Hagar on a charge of murder.

Hagar was in a Portland courtroom as attorneys presented arguments over a legal term called Corpus Delicti. That means a person can not be convicted unless it is proven that an actual crime has been committed. Meaning, a conviction can not come from a confession alone.

“The rule basically says you need evidence of a crime, other than an admission,” said Verne Paradis, Hagar's attorney.

That’s why the case against Hagar wasn’t pursued, even though he first admitted what he had done to police back in 1991. Investigators say Hagar told them he did it because of his own rough upbringing and he was jealous his wife was spending more time with the infant.

“That he wanted his father to hurt based on the way he was raised by his dad. He also spoke of maybe not being ready to be a father, some jealousy involved, and the lack of freedom that comes with having a child,” Maine State Police Detective Jay Pelletier testified.

Based on Hagar’s statements, the former state medical examiner asked that the cause of death be changed.

“To reflect the cause of death as asphyxia due to smothering and the manner of death as homicide,” Dr. Margaret Greenwald testified.

Hagar’s attorney argued that’s still based on his client’s confession and is not reliable evidence.

“She said I can’t tell it’s a smothering. The only reason I can say it is, is because Mr. Hagar says it was,” Paradis said after the hearing concluded.

Paradis is asking that the murder charge be thrown out. If it is not dismissed, he says his client plans to plead guilty to manslaughter under a deal worked out with the state. The judge has asked both sides to submit written briefs before he makes a decision.