QUINCY — They had argued incessantly in recent years, and in a fight four months ago Michael Beaudry broke his father’s ribs, a prosecutor said. Another quarrel erupted Monday, authorities said, and this time the caustic relationship came to a deadly end in front of their Weymouth home.
Beaudry allegedly swung a 3-foot PVC pipe with a 2-inch diameter at his 58-year-old father, striking him in the head. As Ronald Beaudry fell, his head struck the pavement.
A dispute over a BB gun led to the violence, prosecutors said Tuesday, as Michael Beaudry was arraigned in Quincy District Court. He pleaded not guilty to a murder charge.
Ronald Beaudry sought to ensure his son did not use the BB gun in the neighborhood as he had in the past, drawing complaints from neighbors, they said.
Witnesses say the 20-year-old was contrite immediately after he hit his father, saying, “Oh my God, I didn’t mean to do it,” and “I’m sorry, Dad.”
Jack Atwood, Beaudry’s attorney, told Judge Mark Coven that manslaughter would be a more appropriate charge.
“I’m saying that the father would have a pattern of aggression,” Atwood said after the arraignment. “The kid was not an aggressive kid, and he walks away, which I believe was a great irritant to the father.
“As a result of that, as a result of the kid having no job, not getting into the military, it was building and building,” Atwood said. “. . . Eventually, the father got really mad about this.”
Michael Beaudry, a 2011 Weymouth High School graduate, told his family and friends that he was in the process of joining the Army, and had just a few more steps to take before heading off to basic training in the spring, Atwood said.
He is fascinated with military history and keeps several uniforms, including Nazi-style ones with red swastika arm bands, uniforms that bothered his mother, Atwood said. Beaudry posted pictures of himself on Facebook wearing some of those uniforms.
“He and his friends used to get dressed up in Army uniforms, go up in the caves in the woods up here, and they’d play Army,” said Dennis Antonowicz, a neighbor who has known the younger Beaudry since he was a toddler.
“I thought they were a little old to be doing that, in their 20s,” he said.
Neighbors said they never witnessed any animosity between father and son.
“This summer Michael was over there working on his car — he has a hot-rod — and his father was helping him, and they were joking and having a good time,” Antonowicz said.
That description is in contrast to Michael Beaudry’s characterization of their relationship, telling officers that they had been “fighting for years,” and that they “butt heads all the time,” according to a Weymouth police report.
Beaudry told the officers that he felt his father was about to start an argument with him Monday afternoon. Beaudry said he grabbed the PVC pipe and a propane tank to carry to a friend’s house to make a rocket.
His father followed him downstairs into the basement and demanded to talk with him, but Michael Beaudry said he hurried back upstairs, going past his father. As he ran, he heard his father’s keys and “knew he was chasing him,” Beaudry told police.
Beaudry said he turned and swung the pipe he was holding in his left hand, hitting his father in the head in front of the family’s Cross Street home, according to the report.
Beaudry told investigators he started yelling for someone to call 911 and then he ran inside his house to get a shirt to put on his father’s head.
When he rushed inside, the commotion drew the attention of his mother, Shirley Beaudry. She asked her son what happened, according to police.
“I hit him with the pipe,’’ Michael Beaudry told his mother.
The elder Beaudry was pronounced dead at South Shore Hospital at 5 p.m. An autopsy will be conducted to determine cause of death, but a preliminary medical report indicated he suffered severe brain swelling. He was a maintenance worker and a member of the Weymouth American Legion Post 79.
Michael Beaudry was ordered held without bail and is due back in court for a probable cause hearing on Feb. 27.
Shirley Beaudry did not attend Tuesday’s arraignment because she was too distraught, Atwood said. Michael Beaudry’s paternal uncle did attend, as did about six of the defendant’s friends, but they all left without commenting.
Atwood, who pleaded not guilty on Beaudry’s behalf, had a brief talk with the brother-in-law, who carried a message from the defendant’s family. “I was to convey to him [Beaudry] that everybody loves him including his mother, so I’m going to take that as support by the mother,” Atwood said.John Ellement of the Globe staff contributed to this report. Brian Ballou can be reached at Bballou@globe.com.