Max Shacknai fell down the stairs at his father's mansion July 11, 2011. He died a week later.

The mother of a 6-year-old boy who died last summer after falling down the stairs in his father’s Coronado, Calif., mansion is asking authorities to reopen the case.

Max Shacknai fell over a railing and down the stairs at his father's historic John D. Spreckels mansion on July 11, 2011, in what Coronado police called a tragic accident. The child struck the carpeted floor face first, fracturing his forehead. He was not breathing and did not have a pulse when paramedics found him. Max died a week later.

Days after the boy's fall, his father’s girlfriend, Rebecca Zahau, was found hanging nude from a second-story balcony in the same house. The San Diego Sheriff's Department ruled Zahau's July 14 death a suicide.

Timeline of events in the Spreckels mansion deaths

“Things just didn’t add up to me, so I hired independent experts to review the findings,” the boy's mother, Dina Shacknai, said in a statement given to reporters on Monday. “When I started this process all I knew is that I wanted the truth, wherever that led, like any parent would.”

Forensic pathologist Dr. Judy Melinek contributed to the independent investigation, calling the classification of Max’s death "inaccurate."

“It would be more accurate to certify that manner as a homicide, where homicide is defined as death at the hands of another,” Melinek said in the statement.

For more, view NBCSanDiego.com's report on mansion death investigation

Melinek said there is the possibility of a scenario in which Max was assaulted, leading to his fall from the balcony.

Dina Shacknai isn't the only one seeking additional details following the Coronado Police Department’s conclusion of events at the mansion.

Jonah Shacknai, a pharmaceutical company executive and multimillionaire who is divorced from Max's mother, asked California Attorney General Kama Harris to review investigators' findings that his girlfriend killed herself by tying her wrists and ankles and hanging herself.

Zahau’s family also has called for a statewide investigation. The family also appeared on two episodes of the afternoon television show "Dr. Phil" in November.

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Dina Shacknai’s presented her team's findings to the Coronado Police Department last week.

"Even though nothing will bring my only child Maxie back, I owe it to him, as his mother, to make sure the true facts of his death are known,” she said in the statement. “It’s important that his story be told, because this could happen to anyone’s child.”

A police department spokeswoman said authorities will study the new challenge to their investigation.

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