A civil jury in San Diego Superior Court has found Adam Shacknai responsible for the mysterious death of Rebecca Zahau and awarded her family $5 million in punitive damages.

Zahau's July 2011 death at Spreckels Mansion in Coronado, California, had been ruled a suicide by authorities, but in 2013, her family filed a wrongful-death lawsuit against Adam Shacknai, the brother of Jonah Shacknai, Zahau's then-boyfriend, pharmaceutical tycoon Jonah Shacknai.

Standing with Mary Zahau-Loehner, Zahau’s sister, outside the courthouse, plaintiff's attorney C. Keith Greer said the case was never about money.

"[I] asked Mary at the end of the day, ‘Wow, what do we do? … We got a verdict.’ And she says, ‘We got to get the case reopened, that’s it.’ Our job’s not done yet," he said in a news conference on Wednesday after the verdict.

He said Zahau's family is going to petition the sheriff to "to reopen the case to declassify it as a suicide and reclassify it as an open investigation" and use their resources to investigate Zahau's death. "One thing we were really lacking was resources."

"20/20" has been following the Zahau case for years and most recently reported on it in March.

On July 13, 2011, Zahau, 32, was found naked with her feet bound, hands tied behind her back and a shirt stuffed in her mouth, hanging from the second story balcony outside her room. Detectives found a book on a shelf in her room titled "Buckland's Complete Book of Witchcraft," which showed drawings of a rite -- a naked woman with her hands tied behind her back.

A cryptic message -- "She saved him, can you save her" -- was scrawled in black paint in block lettering on the door of her room.

Only she and Adam Shacknai were staying at on the mansion ground the night she died. He said he didn't go into the main house until the next morning, on July 13, 2011, when he discovered Zahau's body. He cut her down from the rope and called 911.

Adam Shacknai had flown in from Tennessee after hearing that his 6-year-old nephew, Max Shacknai, Jonah Shacknai's son, had somehow fallen over a second-floor railing in the house while he was in Zahau's care just days earlier.

Suspicion surrounding Zahau's death immediately fell on Adam Shacknai who took a lie detector test the day she died. The results were inconclusive. Adam Shacknai denied having any involvement in Zahau's death and the authorities cleared him of any involvement in Zahau's death.

Authorities determined that she had tied her own hands and feet, gagged herself and committed suicide after listening to a voicemail from Jonah Shacknai informing her of Max's grave condition. Three days later, Max died in the hospital.

The Zahau family, however, refused to accept the suicide ruling and took the case to the media. The Zahau family exhumed Zahau's remains and renowned forensic pathologist Dr. Cyril Wecht performed a second autopsy.

On "Dr. Phil," Wecht said he found there was enough evidence to suspect foul play.

The Zahaus petitioned the California Attorney General's Office to reopen the case but their request was denied.

In July 2013, two years after Zahau was found dead, her family filed a wrongful-death suit that named Adam Shacknai, along with Jonah Shacknai's ex-wife and Max's mother, Dina Shacknai, and her twin sister, Nina Romano, as defendants. Jonah Shacknai was not named in the lawsuit.

Dina Shacknai called the allegations made against her in the lawsuit a "disgraceful abuse of the legal system." She told ABC News, "To create this fantastical story and insert us in something like this was beyond the pale of humane."

After hospital footage revealed that Dina Shacknai was at the hospital the night of Zahau's death, the attorney for the Zahau family dropped her and her sister from the lawsuit and publicly apologized.

Adam Shacknai remained named in the family's lawsuit.

On the night of Zahau's death, Adam Shacknai says he never left the guest house. Only Zahau's fingerprints and DNA were found at the scene, according to authorities, even though Adam Shacknai told them he had cut Zahau down from the rope, then performed chest compressions and mouth-to-mouth resuscitation in an effort to revive her.

In his interview for “20/20”, Jonah Shacknai said he believes that his brother is innocent of any wrongdoing and that the lawsuit is outrageous.

"This is all about finding the truth," Zahau-Loehner said in March. "That people understand that my sister did not commit suicide."