LEWISTON – Scott Poirier told police he shot his father in the throat because his father had sexually abused him and he wanted to protect his own children, according to an affidavit released Monday.

The Sabattus man told police he was molested by his father, Roland Poirier, and he suspected a sibling had been victimized as well, according to the document, signed by a state police detective.

Scott Poirier, 34, is charged with murder in the Nov. 8 shooting of his father at the elder man’s home on Grove Street.

Roland Poirier was shot in the neck as he sat at the table celebrating his 65th birthday with a roomful of friends and family members, police said. Investigators said Scott Poirier stood in the yard of the home and shot his father through a sliding glass door.

Hours before the shooting, Scott Poirier had become emotionally upset, punching holes in the walls of his Davis Lane home, according to his roommate, whose descriptions of the incident were included in the affidavit.

Police believe Scott Poirier went to his father’s house at about 7:45 p.m. with a loaded .270-caliber rifle.

“Lies will end tonight,” Poirier is quoted as telling a relative in a telephone call shortly before the shooting. “Take care of my boys; I am a good dad.”

Scott Poirier has four sons. The oldest are 6-year-old twins.

“Scott advised me that he had been sexually abused by his father, Roland Poirier, when he was younger,” Maine State Police Detective Mark Lopez wrote in the search warrant affidavit. “Scott went on to say that he had four sons and it was not going to happen to them and that is why he went to his father’s home and shot him in the throat.”

Police investigating the shooting obtained a warrant to search Scott Poirier’s pickup truck and his home as well as contents of a cell phone. Police were searching for “written, typed or electronic notes or journals regarding past sexual abuse of Scott Poirier by Roland Poirier or evidence of premeditation of this crime.”

Police did not disclose what was found during the searches.

The elder Poirier, a successful operator of a landscape business, was never charged with any crime related to sexual abuse. Police said they are not aware of any complaints against him in the past.

Scott Piorier is scheduled to appear in court Friday for a hearing on the prosecution’s motion for a psychological exam.

He is being held without bail at the Androscoggin County Jail in Auburn pending a court hearing later this month. His lawyer, Thomas Peters, declined to comment on the case Monday.