HOULTON ( AP) — A 10-year-old boy who “cowered in fear” and a 30-year-old man who lived down the road were fatally stabbed simply because they happened to be in the home of Thayne Ormsby’s intended victim, a prosecutor told jurors Monday.

The defendant went to Jeffrey Ryan’s home in June 2010 intending to kill him, not realizing Ryan’s 10-year-old son, Jesse, and a family friend were also in the home, Deputy Attorney General William Stokes said.

All three were killed on Ryan’s property in Amity, a quiet farming and logging town with about 200 residents.

The Bangor Daily News reports that Ormsby’s lawyer told jurors in Aroostook County Superior Court in Houlton that he’ll seek to put the events “into context” during the trial, which is expected to last up to two weeks.

Ormsby, 21, is charged with three counts of murder in the deaths of the 55-year-old Ryan, Ryan’s son and Jason Dehahn, a neighbor, on June 22, 2010. He’s also charged with arson for allegedly stealing Ryan’s pickup truck and setting it on fire on a back road.

Stokes said Ormsby first killed Jeffrey Ryan outside near a woodshed before entering the home and finding Dehahn and the boy playing video games.

Ormsby stabbed Dehahn in the chest before chasing the terrified boy down the hall and into a bedroom, where the boy was stabbed in the back, Stokes said. The boy was stabbed as he “cowered in fear,” and his body was on its hands and knees when it was discovered, he said.

Dehahn managed to get outside where he was nearly decapitated when Orsmby slashed his throat and stabbed him repeatedly in the back, Stokes said.

Opening statements and testimony got under way after three days of questioning more than 100 potential jurors. The jury was seated Monday morning, and Justice E. Allen Hunter denied a defense motion to move the trial because of pre-trial publicity in Aroostook County.

Ormsby grew up in the Ellsworth and went to Ellsworth High School until he dropped out his senior year. At the time of the killings, he was living with Robert and Joy Strout in the nearby town of Orient.

Robert Strout pleaded guilty to helping Ormsby destroy evidence by setting fire to Jeffrey Ryan’s pickup truck before driving Ormsby to his son’s house in Dover, N.H.