NORTH HAVEN (AP) – Maine State Police on Monday continued investigating a weekend killing in which a 23-year-old man was charged in the stabbing death of his older brother.

Enoch Petrucelly was charged Sunday with murder in the death of Michael Petrucelly, 24, at a home of an acquaintance on this Penobscot Bay island. The brothers live in Palmyra and were visiting the island over the weekend.

The cause of death was multiple stab wounds to the chest, a spokewoman for the state medical examiner’s office said after an autopsy Monday.

Officials were called to a Crabtree Point Road residence at about 5:40 a.m. Sunday with a report of an unresponsive man, said Lt. Gary Wright. When officials arrived, the older brother was dead, he said.

Wright said the death was being treated as a “domestic violence homicide.” Detectives on Monday continued processing the home and interviewing people on the island and on the mainland, he said.

Police didn’t reveal the type of weapon or other details surrounding the death, but Wright said more information could be forthcoming when Petrucelly makes his initial court appearance, which is scheduled for Tuesday morning in Knox County Superior Court. Petrucelly was being held Monday in the Knox County Jail in Rockland.

North Haven residents were shocked to hear that a murder occurred on their small island, located about a dozen miles from Rockland. It has year-round population of less than 400, but the numbers swell in July and August with the arrival of summer residents and vacationers.

“It’s horrifying,” Lisa Shields, a year-round resident, told WCSH-TV. “It’s terrifying that this could happen in such a small community that’s so closely knit.”

Shields said she thinks this might be the first homicide ever on the island and is worried it may change the face of North Haven.

There have been 23 homicides in Maine so far this year, which already exceeds the annual average of about 20. Of the 23, 15 have been classified as domestic violence homicides, Wright said.