The adult sister of a 9-year-old boy who is charged with killing their mother says he has mental health problems and that he probably just “snapped” on the day of the shooting.

Reagan Martin told that she doesn’t know how the boy got access to a gun. The 23-year-old, who has a different last name than her mother and brother, says hunting rifles are usually locked up in the home in southern Michigan’s St. Joseph County. She also says she believes her brother wanted to scare their mother, not kill her.

“My mom would not want him to be labeled a murderer,” said Martin. “Her whole world revolved around him.”

Police say the boy killed his 51-year-old mother at their home on Monday. The Associated Press is not identifying the mother because to do so would identify the child.

Martin says her brother was adopted in 2016 but has lived with the family since he was very young. She told The Detroit News that the boy had a rough upbringing.

“But she took him in to care for him as her own,” said Martin. “She had been trying to reach out for help by his family doctor … who blamed her for (these) issues.”

Martin said her mother tried to reach out to county mental services but her insurance did not cover the appointments.

“My mother(‘s) death lays in the hands of people failing to educate in mental issues and failing to listen when helped is being begged for,” she said.

Martin said things had dramatically worsened in the last two weeks after the boy’s medication had changed.

He started “hitting, kicking and throwing stuff,” she said.

Martin said her mother was a nurse up until a few years ago when she determined she should stay home with her son.

“I’m angry, don’t get me wrong,” Martin said. “But he’s my little brother and he needs help. I hope he gets it.”

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