A Farmington man was arrested Friday after being indicted on murder charges in connection with the 1979 death of his 4-month-old son.

Burton “Ben” Hagar, 62, was arrested just before noon at his home on Marvel Street by state police detectives, Stephen McCausland, spokesman for the Maine Department of Public Safety, said in a news release.

Hagar's son, Nathan Hagar, was found unresponsive in the family’s apartment on School Street in Brunswick and was pronounced dead at Parkview Hospital in Brunswick on May 9, 1979.

Investigators originally believed the boy died of SIDS, but state police quietly reopened the case in 1991. An investigation conducted over the past year, which included the new Unsolved Homicide Unit, led to the Attorney General’s Office presenting the case to a grand jury this week.

“There are more than 100 Maine unsolved homicides and the new unit is reviewing each case," Col. Robert Williams, chief of the Maine State Police, said in the release. "The hard work of this dedicated group from State Police and the Attorney General’s Office have brought this first unsolved homicide to this point, and there will be other success stories as their work continues.”

McCausland said the death of Hagar's son is the oldest unsolved homicide case state police have ever resolved.

Hagar was transported to the Franklin County Jail. He will be arraigned Wednesday at 1 p.m. in Cumberland County Superior Court in Portland.