SAN DIEGO - The evidence room has been unlocked in the mysterious death of a woman at the Spreckels Mansion in Coronado.

In 2011, Rebecca Zahau was found dead at the historic home -- her hands and legs were bound by a red rope, which was also used to hang her nude body over a balcony on the property.

While the San Diego County Sheriff's Department ruled Zahau's death a suicide, her family insists she was a murder victim.

Attorney Keith Greer, who is representing the Zahau family in a wrongful death lawsuit, gave 10News exclusive access to pictures and video from the evidence room that he said holds countless clues that point to murder.

Greer said, "The evidence is very strong … One of the unusual things about this case is there is really a lack of DNA."

"What do you attribute that to?" asked 10News anchor Itica Milanes.

"I think somebody cleaned everything up," Greer answered.

RELATED: New evidence proves Zahau murdered

One of the most perplexing pieces of evidence is a bedroom door with a hand-painted riddle on it that says: "She saved him. Can he save her?"

"The note was written by the person who killed Rebecca," said Greer.

Greer said the sheriff's department never analyzed the handwriting.

However, Greer did, and his experts say it implicates one person -- Adam Shacknai, the man named in the civil suit.

Adam Shacknai is the brother of Zahau's boyfriend, Jonah, a pharmaceutical tycoon. Adam was staying in his guest house at the time.

As for the knots that bound Zahau, Greer said, "This wasn't a novice. You had to have some understanding of knot tying. There are marine knot characteristics involved and principles which is consistent with Adam being a tugboat captain."

RELATED: Rebecca Zahau wrongful death lawsuit heads to trial

Investigators believe Zahau was overwhelmed with guilt and ended her life because of an accident in the home two days earlier that led to the eventual death of Jonah Shacknai's young son Max, who was under Zahau's care.

Greer has a theory about why Sheriff Bill Gore was so quick to wrap up the investigation by insisting it was suicide.

"I think they were having heavy pressure from Jonah Shacknai," said Greer. "Would she humiliate her family and embarrass her family if that's the way she was going to kill herself? No way. No way."

Dina Shacknai, Jonah's former wife and the mother of Max, is also named in the lawsuit.

The Zahau family had the opportunity to settle the lawsuit for millions of dollars, but they refused. Greer said for the family, this is about honor.

A trial is scheduled to begin in June.