Mansion Deaths Put Spotlight on Past Accusations of Violence By Jonah Shacknai

CORONADO, Calif. July 21, 2011— -- The investigation into two deaths at the historic Spreckels Mansion has put a spotlight on the turbulent marriage of the mansion's owner Jonah Shacknai and the accusations of violence that surrounded the marriage.

Shacknai, the millionaire owner of a pharmaceutical company, recently lost his 6-year-old son Max who died Sunday of injuries suffered when he fell down the stairs at the mansion last week. His girlfriend Rebecca Zahau was found at the mansion last Wednesday with her hands bound behind her back, her ankles tied together, and a rope around her neck.

Autopsies are being conducted on both victims and the San Diego sheriff's office said it's unclear if the two deaths are related. Police said that 15 detectives have been assigned to the investigation.

Despite the circumstances of Zahau's death police say they still haven't ruled out suicide.

Shacknai was not home during either incident, police say, but the tragedies have brought a focus on his life.

Shacknai, 54, has been married twice. He divorced Kimberly Shacknai in 1993. His subsequent marriage to Max's mother Dina Shacknai also ended in divorce with accusations on both sides of verbal and physical assault.

In Arizona police reports obtained this week by ABC News Shacknai's ex-wife Dina Shacknai said she was "scared of what he is capable of doing to me physically … and the lengths he would go to try to 'destroy' me."

Shacknai denied the allegations, telling police Dina had filed "false and misleading reports."

September 2008 photos from Paradise Valley police show scratches on Dina Shacknai's back.

She told police she was attacked by her husband's German shepherd, just as she had been several times in the past. She gave police photos from 2006 showing cuts to her arms and knees, from incidents where Dina claimed the dog bit her because the dog is "very sensitive to changes in voice tone and body language and any tense exchange with Jonah may result in an attack response."

She told police, however, that Jonah didn't command the dog to attack her.

Shacknai said his wife came at him and tried to choke him, according to the documents.

In January 2009, Dina Shacknai accused her husband of elbowing her in the breast. Shacknai told police he was trying to "nudge" her out of his car because she had reached for the ignition and tried to grab the steering wheel as he attempted to drive away. He also claimed he had been assaulted "several times" by his wife.

Jonah and Dina Shacknai sent out a statement earlier this week saying the records release "pains us greatly" especially now after losing their son.

"While our marriage did not work out as either of us had hoped, it did produce a wonderful son, Max, whom both of us loved very much," the statement read. "His loss is unimaginable. These police reports are not reflective of the totality or the precise details of the events during a difficult time in our marriage that we worked through together."

Shacknai is not considered a person of interest in the Zahau investigation. Today police confirmed Shacknai has left San Diego.

People who saw Shacknai and Zahau together said the couple had been dating for three years and seemed happy together. Zahau, 32, also seemed happy to be with Max and had a close relationship with the boy.

An exclusive photo obtained by "Good Morning America" of Jonah Shacknai and Rebecca Zahau.

Markey, who often saw the two together at Hollywood Fitness in Coronado, said she was "the sweetest girl you could possibly imagine."

"Nothing but good things to say about her. It's horrible for this to happen to anybody, but for her it was a shock to me because she was the nicest girl you could meet," Markey said.

While police investigate, Zahau's sister Mary Zahau-Loehner does not believe that she committed suicide.

The sisters spoke the night before Zahau died, she said, and Zahau talked about her plans for the following day.

"She was going to call mom and dad the next morning and text me throughout the day with updates on Max," said Zahau-Loehner. "She was very hopeful. She had to be strong and there for Jonah."

Zahau and Shacknai seemed happy together, her sister said.

Police said it "could take weeks" for forensics and lab results on Zahau's death, just one element of the lengthy investigation to determine whether her death was a suicide.