McVay's brother, Tony Miller, said his nephew argued with his mother just before she died because he didn't want to carry in the firewood.
"He had anger issues, and she overlooked those anger issues," said Miller, who lives in Louisville, Ky. "It was her son. She loved him very much."
Four weapons were found in the boy's bedroom after the shooting. On his bed were the .22-caliber rifle believed to be the weapon that killed his mother and a 12-gauge shotgun. On the gun rack were two more .22-caliber rifles, Holmes County Sheriff's Chief Deputy Nathan Fritz said. Paramedics found McVay lying facedown on her living room floor, and she was pronounced dead at the scene.
Authorities went to the house, a two-car garage converted into a living space, after a neighbor called a sheriff's dispatcher to say McVay's son had come to her home and said he had just shot his mother.
"I'm her neighbor. I'm over here. She's bleeding from her head," the neighbor tells a dispatcher.
When the dispatcher asks "Is she breathing?" the neighbor answers, "No, she's bleeding."
"The neighbors came over and got me and said the mom got shot in the head," the neighbor says.
McVay had separated from her husband, Mike McVay, two weeks ago, Miller said. The guns found in the boy's room once belonged to his grandfather, but they were given to him by his father, Miller said. He didn't know when the boy received the guns.
Before Deborah McVay died, she had argued with her husband about the weapons' presence in her son's room, Miller said.
"She knew, and she did not like it, and she kept bringing the issue up about getting rid of them," he said. "But every time she did, there was an argument about it with the father."
Mike McVay could not be reached for comment about his wife's death.
The 10-year-old appeared in court Monday in an orange jumpsuit, his hands and feet cuffed. A judge ordered he remain in Richland County Juvenile Detention as authorities investigate the shooting.
"It's not unusual for boys of that age to hunt and shoot," Fritz said. "I think it's unusual that those weapons were permitted to be in the boy's bedroom."
The boy lived with his mother and 15-year-old sister, who was present at the time of the shooting, in the small one-story dwelling, Fritz said. An empty shell casing belonging to a .22-caliber rifle was found in the living area after the shooting.
"He'd come out here and practice with the BB gun," Miller said. "And from what I've seen of him he seemed a little responsible with the BB gun. But, like I said, he did have anger issues."
The investigation has unearthed previous disciplinary problems in the boy's life but no serious violence. In December 2006, Deborah McVay called the sheriff's office to complain about a school bus driver who disciplined the boy, Fritz said.
"He was being disruptive, and the bus driver had to stop the bus," Fritz said, "and grabbed him by the jacket and sat him down."
No charges were filed by the family against the driver.
In September 2007, the boy was disciplined for hitting his elementary school principal in the face and chest with a dustpan, Fritz said. The principal had been escorting the boy to the gymnasium for a time out after he had been disruptive in class, and the boy grabbed the dustpan when they reached the gym, Fritz said.
The incident was reported to the sheriff's office as an "unruly complaint" and was referred to the prosecutor's office, but sheriff's deputies didn't know the outcome.
Killbuck Elementary School Principal David Wade confirmed that the boy was a student there for years but wouldn't comment further. He deferred all inquiries to the district's superintendent, who didn't respond to a request for comment Tuesday.
The boy was transferred to Clark Elementary School, which specializes in children with behavioral problems or special needs, Fritz said. The principal at Clark Elementary also declined to comment.
County prosecutor Steve Knowling said authorities do not plan to prosecute the boy as an adult. Defense attorney Andrew Hyde said he plans to argue for the boy's release so he can stay with a family member.
It's a rarity for a young child to be suspected of killing anyone. According to FBI crime statistics, 11 children ages 5 to 12 were murder defendants in 2009 -- 10 boys and one girl.
Hyde said he did not have the facts of the case, including any information on whether the shooting may have been accidental, and he couldn't comment further.