MASARDIS – No one knows why Michael W. MacDonald died.

Not police, not neighbors, not even some family members.

But at 1 a.m. Thursday, his 25-year-old son, also named Michael MacDonald, showed up at the dispatch window of the Aroostook County Jail in Houlton and turned himself in, saying that Maine State Police wanted him for questioning in his father’s death.

He has been charged with the murder of his 57-year-old father, who lived in a home on Route 11 in Masardis, a central Aroostook County town of about 200.

He was being held without bail Thursday at the Houlton jail and will make his first appearance in District Court in Presque Isle today.

The elder MacDonald had been found by state police late Wednesday night, face down on the linoleum floor of his kitchen. Maine State Police Sgt. John Cote said the condition of the body made clear that a homicide had occurred.

But he and other investigators would not give details, including how MacDonald was killed.

Some information, including cause of death, could be released today by the State Medical Examiner’s Office, which has scheduled an autopsy.

Investigators would not explain what led them to MacDonald’s body, saying only that police went to the home after receiving a call from a family friend requesting that they check on the man’s well-being. Stephen McCausland, spokesman for the Department of Public Safety, would not indicate Thursday what prompted the family friend to call.

After police located and charged the younger MacDonald, they spent Thursday collecting evidence at the father’s home and interviewing family members and friends, Cote said.

They reported that the younger MacDonald had been spending a few nights a week at his father’s house and the rest of his time with friends. There was frustration on the son’s part about where he wanted to live, Cote said.

The younger MacDonald has a criminal history, which includes at least one assault.

“It’s unbelievable that something like that would happen here,” Masardis Town Manager Judie MacDonald said Thursday. “You hear about stuff like that in New York, but it’s not supposed to happen here in a small town.”

Still, this is the fourth murder in 25 years that has taken place in the town. The other three never have been solved, the town manager said, and this one is leaving residents shocked.

“Maybe it was a family squabble,” she said, shrugging.

Even Ernestine Craig, the elder MacDonald’s aunt, said she had no idea why her nephew is dead.

“Why it happened, I couldn’t tell you,” Craig said Thursday from her home in Masardis.

“He was my sister’s boy,” she said, shaking her head and looking out the window as tears welled up in her eyes.