Justyna Zubko Valva, the mother of an 8-year-old boy who police say was killed by his father and his fiancee, says she has been sounding the alarm about Michael Valva’s abusive behavior for years.

Suffolk Police Commissioner Geraldine Hart said Thomas Valva was kept in an unheated garage overnight last week, amid bitterly cold temperatures. Officials say at the time of his death, the boy's body temperature was 76 degrees.

The medical examiner ruled his death a homicide with a contributing factor of hypothermia.

“This is so unfortunate that it has to get to the point that a child is dead for somebody to actually do something in this case,” says Justyna Zubko Valva.

MORE: Police: Center Moriches boy was kept in garage amid freezing temperatures before his death 

The mother says she has been going through a bitter divorce and child custody battle for her three boys. She claims she lost full custody of the children two years ago because of false allegations.

She says this whole time Child Protective Services did nothing to protect her kids.

“Every time, I kept telling the judge – ‘If you're not going to remove the children, they are going to die under his care and custody,’” she said. “There was evidence, hard evidence. Reports filed. Children were telling me, too, about the abuse.”

Justyna Zubko Valva says her Twitter feed has documented abuse that her children endured from Michael Valva.

She also gave News 12 documents that she said are from the East Moriches school district. The paperwork alleges Thomas Valva and his older brother Anthony were crying in school because they were not allowed to eat at home.

Her paperwork also says Thomas Valva once came to school with a black eye, another time with a bruise on his forehead, because the father threw a book bag at his head.

“There's a report my older son was locked up in the garage with no heat. He came to school with frostbite on his hands and feet,” says Justyna Zubko Valva.

Suffolk police said they are in contact with the Department of Social Services.

“We are going to look at every interaction this child had with the system and investigate every avenue,” said Commissioner Hart.

The Suffolk County Department of Social Services told News 12 that it was involved with the Valva and Pollina family. It says petitions for child neglect were filed in Suffolk County Family Court in 2018.

There was court-ordered home supervision for a period of one year. Orders of protection were issued for the parents to refrain from harmful behaviors toward the children.

It also says CPS investigated additional complaints relating to the family. DSS says it is now reviewing the management of the case to ensure that all protocols were followed.

Justyna said she has now been granted temporary custody of her 10- and 6-year-old boys.

“My children are back with me. Thank god. They are safe,” she said. “There is such a long process of healing…They've been traumatized by this whole situation by the way they were treated and abused and neglected. It's going to take a long time.”

Michael Valva, an NYPD transit officer, and his fiancée Angela Pollina were charged with second-degree murder.